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1 |
Print a literal string on standard output
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2 |
Loop to execute some code a constant number of times
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3 |
Like a function which doesn't return any value, thus has only side effects (e.g. Print to standard output)
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Alternative implementation:
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4 |
Create a function which returns the square of an integer
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5 |
Declare a container type for two floating-point numbers x and y
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6 |
Do something with each item x of the list (or array) items, regardless indexes.
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Alternative implementation:
Alternative implementation:
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7 |
Print each index i with its value x from an array-like collection items
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Alternative implementation:
Alternative implementation:
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8 |
Create a new map object x, and provide some (key, value) pairs as initial content.
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Alternative implementation:
Alternative implementation:
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9 |
The structure must be recursive because left child and right child are binary trees too. A node has access to children nodes, but not to its parent.
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Alternative implementation:
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10 |
Generate a random permutation of the elements of list x
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11 |
The list x must be non-empty.
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Alternative implementation:
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12 |
Check if the list contains the value x.
list is an iterable finite container. |
Alternative implementation:
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13 |
Access each key k with its value x from an associative array mymap, and print them.
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Alternative implementation:
Alternative implementation:
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14 |
Pick a random number greater than or equals to a, strictly inferior to b. Precondition : a < b.
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15 |
Pick a random integer greater than or equals to a, inferior or equals to b. Precondition : a < b.
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16 |
Call a function f on every node of binary tree bt, in depth-first infix order
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Alternative implementation:
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17 |
The structure must be recursive. A node may have zero or more children. A node has access to its children nodes, but not to its parent.
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19 |
Reverse the order of the elements of the list x.
This may reverse "in-place" and destroy the original ordering. |
Alternative implementation:
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20 |
Implement a function search which looks for item x in a 2D matrix m.
Return indices i, j of the matching cell. Think of the most idiomatic way in the language to return the two values at the same time. |
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21 |
Swap the values of the variables a and b
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22 |
Extract the integer value i from its string representation s (in radix 10)
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Alternative implementation:
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23 |
Given a real number x, create its string representation s with 2 decimal digits following the dot.
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Alternative implementation:
Alternative implementation:
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24 |
Declare a new string s and initialize it with the literal value "ネコ" (which means "cat" in japanese)
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25 |
Share the string value "Alan" with an existing running process which will then display "Hello, Alan"
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Alternative implementation:
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26 |
Declare and initialize a matrix x having m rows and n columns, containing real numbers.
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27 |
Declare and initialize a 3D array x, having dimensions boundaries m, n, p, and containing real numbers.
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28 |
Sort the elements of the list (or array-like collection) items in ascending order of x.p, where p is a field of the type Item of the objects in items.
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Alternative implementation:
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29 |
Remove i-th item from list items.
This will alter the original list or return a new list, depending on which is more idiomatic. Note that in most languages, the smallest valid value for i is 0. |
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30 |
Launch the concurrent execution of the procedure f with parameter i from 1 to 1000.
Tasks are independent and f(i) doesn't return any value. Tasks need not run all at the same time, so you may use a pool. |
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31 |
Create the recursive function f which returns the factorial of the non-negative integer i, calculated from f(i-1)
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32 |
Create function exp which calculates (fast) the value x power n.
x and n are non-negative integers. |
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33 |
Assign to the variable x the new value f(x), making sure that no other thread may modify x between the read and the write.
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Alternative implementation:
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34 |
Declare and initialize a set x containing unique objects of type T.
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35 |
Implement a function compose (A -> C) with parameters f (A -> B) and g (B -> C), which returns the composition function g ∘ f
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Alternative implementation:
Alternative implementation:
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36 |
Implement a function compose which returns composition function g ∘ f for any functions f and g having exactly 1 parameter.
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37 |
Transform a function that takes multiple arguments into a function for which some of the arguments are preset.
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38 |
Find substring t consisting in characters i (included) to j (excluded) of string s.
Character indices start at 0 unless specified otherwise. Make sure that multibyte characters are properly handled. |
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39 |
Set the boolean ok to true if the string word is contained in string s as a substring, or to false otherwise.
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40 |
Declare a Graph data structure in which each Vertex has a collection of its neighbouring vertices.
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41 |
Create the string t containing the same characters as the string s, in reverse order.
The original string s must remain unaltered. Each character must be handled correctly regardless its number of bytes in memory. |
Alternative implementation:
Alternative implementation:
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42 |
Print each item v of list a which is not contained in list b.
For this, write an outer loop to iterate on a and an inner loop to iterate on b. |
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43 |
Look for a negative value v in 2D integer matrix m. Print it and stop searching.
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Alternative implementation:
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44 |
Insert the element x at position i in the list s. Further elements must be shifted to the right.
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Alternative implementation:
Alternative implementation:
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45 |
Sleep for 5 seconds in current thread, before proceeding with the next instructions.
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46 |
Create the string t consisting of the 5 first characters of the string s.
Make sure that multibyte characters are properly handled. |
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47 |
Create string t consisting in the 5 last characters of string s.
Make sure that multibyte characters are properly handled. |
Alternative implementation:
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48 |
Assign to variable s a string literal consisting in several lines of text, including newlines.
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Alternative implementation:
Alternative implementation:
Alternative implementation:
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49 |
Build list chunks consisting in substrings of the string s, separated by one or more space characters.
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Alternative implementation:
Alternative implementation:
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50 |
Write a loop that has no end clause.
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51 |
Determine whether the map m contains an entry for the key k
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52 |
Determine whether the map m contains an entry with the value v, for some key.
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53 |
Concatenate elements of string list x joined by the separator ", " to create a single string y.
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Alternative implementation:
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54 |
Calculate the sum s of the integer list or array x.
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Alternative implementation:
Alternative implementation:
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55 |
Create the string representation s (in radix 10) of the integer value i.
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56 |
Fork-join : launch the concurrent execution of procedure f with parameter i from 1 to 1000.
Tasks are independent and f(i) doesn't return any value. Tasks need not run all at the same time, so you may use a pool. Wait for the completion of the 1000 tasks and then print "Finished". |
Alternative implementation:
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57 |
Create the list y containing the items from the list x that satisfy the predicate p. Respect the original ordering. Don't modify x in-place.
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58 |
Create the string lines from the content of the file with filename f.
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Alternative implementation:
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59 |
Print the message "x is negative" to standard error (stderr), with integer x value substitution (e.g. "-2 is negative").
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60 |
Assign to x the string value of the first command line parameter, after the program name.
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Alternative implementation:
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61 |
Assign to the variable d the current date/time value, in the most standard type.
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62 |
Set i to the first position of string y inside string x, if exists.
Specify if i should be regarded as a character index or as a byte index. Explain the behavior when y is not contained in x. |
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63 |
Assign to x2 the value of string x with all occurrences of y replaced by z.
Assume occurrences of y are not overlapping. |
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64 |
Assign to x the value 3^247
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65 |
From the real value x in [0,1], create its percentage string representation s with one digit after decimal point. E.g. 0.15625 -> "15.6%"
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Alternative implementation:
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66 |
Calculate the result z of x power n, where x is a big integer and n is a positive integer.
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67 |
Calculate binom(n, k) = n! / (k! * (n-k)!). Use an integer type able to handle huge numbers.
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68 |
Create an object x to store n bits (n being potentially large).
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69 |
Use seed s to initialize a random generator.
If s is constant, the generator output will be the same each time the program runs. If s is based on the current value of the system clock, the generator output will be different each time. |
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70 |
Get the current datetime and provide it as a seed to a random generator. The generator sequence will be different at each run.
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71 |
Basic implementation of the Echo program: Print all arguments except the program name, separated by space, followed by newline.
The idiom demonstrates how to skip the first argument if necessary, concatenate arguments as strings, append newline and print it to stdout. |
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74 |
Compute the greatest common divisor x of big integers a and b. Use an integer type able to handle huge numbers.
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75 |
Compute the least common multiple x of big integers a and b. Use an integer type able to handle huge numbers.
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76 |
Create the string s of integer x written in base 2.
E.g. 13 -> "1101" |
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77 |
Declare a complex x and initialize it with value (3i - 2). Then multiply it by i.
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78 |
Execute a block once, then execute it again as long as boolean condition c is true.
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79 |
Declare the floating point number y and initialize it with the value of the integer x .
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80 |
Declare integer y and initialize it with the value of floating point number x . Ignore non-integer digits of x .
Make sure to truncate towards zero: a negative x must yield the closest greater integer (not lesser). |
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81 |
Declare the integer y and initialize it with the rounded value of the floating point number x .
Ties (when the fractional part of x is exactly .5) must be rounded up (to positive infinity). |
Alternative implementation:
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82 |
Find how many times string s contains substring t.
Specify if overlapping occurrences are counted. |
Alternative implementation:
Alternative implementation:
Alternative implementation:
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83 |
Declare the regular expression r matching the strings "http", "htttp", "httttp", etc.
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84 |
Count number c of 1s in the integer i in base 2.
E.g. i=6 → c=2 |
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85 |
Write boolean function addingWillOverflow which takes two integers x, y and return true if (x+y) overflows.
An overflow may be above the max positive value, or below the min negative value. |
Alternative implementation:
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86 |
Write the boolean function multiplyWillOverflow which takes two integers x, y and returns true if (x*y) overflows.
An overflow may reach above the max positive value, or below the min negative value. |
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87 |
Exit immediately.
If some extra cleanup work is executed by the program runtime (not by the OS itself), describe it. |
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88 |
Create a new bytes buffer buf of size 1,000,000.
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89 |
You've detected that the integer value of argument x passed to the current function is invalid. Write the idiomatic way to abort the function execution and signal the problem.
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Alternative implementation:
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90 |
Expose a read-only integer x to the outside world while being writable inside a structure or a class Foo.
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Alternative implementation:
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93 |
Implement the procedure control which receives one parameter f, and runs f.
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94 |
Print the name of the type of x. Explain if it is a static type or dynamic type.
This may not make sense in all languages. |
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95 |
Assign to variable x the length (number of bytes) of the local file at path.
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96 |
Set the boolean b to true if string s starts with prefix prefix, false otherwise.
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97 |
Set boolean b to true if string s ends with string suffix, false otherwise.
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98 |
Convert a timestamp ts (number of seconds in epoch-time) to a date with time d. E.g. 0 -> 1970-01-01 00:00:00
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Alternative implementation:
Alternative implementation:
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99 |
Assign to the string x the value of the fields (year, month, day) of the date d, in format YYYY-MM-DD.
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Alternative implementation:
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100 |
Sort elements of array-like collection items, using a comparator c.
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101 |
Make an HTTP request with method GET to the URL u, then store the body of the response in the string s.
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Alternative implementation:
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105 |
1
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106 |
Assign to string dir the path of the working directory.
(This is not necessarily the folder containing the executable itself) |
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108 |
Print the value of variable x, but only if x has been declared in this program.
This makes sense in some languages, not all of them. (Null values are not the point, rather the very existence of the variable.) |
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109 |
Set n to the number of bytes of a variable t (of type T).
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110 |
Set the boolean blank to true if the string s is empty, or null, or contains only whitespace ; false otherwise.
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111 |
From current process, run program x with command-line parameters "a", "b".
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Alternative implementation:
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112 |
Print each key k with its value x from an associative array mymap, in ascending order of k.
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Alternative implementation:
Alternative implementation:
Alternative implementation:
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113 |
Print each key k with its value x from an associative array mymap, in ascending order of x.
Multiple entries may exist for the same value x. |
Alternative implementation:
Alternative implementation:
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115 |
Set boolean b to true if date d1 is strictly before date d2 ; false otherwise.
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116 |
Remove all occurrences of string w from string s1, and store the result in s2.
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117 |
Set n to the number of elements of the list x.
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118 |
Create the set y from the list x.
x may contain duplicates. y is unordered and has no repeated values. |
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119 |
Remove duplicates from the list x.
Explain if the original order is preserved. |
Alternative implementation:
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120 |
Read an integer value from the standard input into the variable n
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Alternative implementation:
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121 |
Listen UDP traffic on port p and read 1024 bytes into the buffer b.
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122 |
Create an enumerated type Suit with 4 possible values SPADES, HEARTS, DIAMONDS, CLUBS.
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123 |
Verify that predicate isConsistent returns true, otherwise report assertion violation.
Explain if the assertion is executed even in production environment or not. |
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124 |
Write the function binarySearch which returns the index of an element having the value x in the sorted array a, or -1 if no such element exists.
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125 |
measure the duration t, in nanoseconds, of a call to the function foo. Print this duration.
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126 |
Write a function foo that returns a string and a boolean value.
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Alternative implementation:
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128 |
Call a function f on every node of a tree, in breadth-first prefix order
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131 |
Execute f1 if condition c1 is true, or else f2 if condition c2 is true, or else f3 if condition c3 is true.
Don't evaluate a condition when a previous condition was true. |
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132 |
Run the procedure f, and return the duration of the execution of f.
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133 |
Set boolean ok to true if string word is contained in string s as a substring, even if the case doesn't match, or to false otherwise.
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Alternative implementation:
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134 |
Declare and initialize a new list items, containing 3 elements a, b, c.
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135 |
Remove at most 1 item from list items, having the value x.
This will alter the original list or return a new list, depending on which is more idiomatic. If there are several occurrences of x in items, remove only one of them. If x is absent, keep items unchanged. |
Alternative implementation:
Alternative implementation:
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136 |
Remove all occurrences of the value x from list items.
This will alter the original list or return a new list, depending on which is more idiomatic. |
Alternative implementation:
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137 |
Set the boolean b to true if the string s contains only characters in the range '0'..'9', false otherwise.
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Alternative implementation:
Alternative implementation:
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138 |
Create a new temporary file on the filesystem.
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139 |
Create a new temporary folder on filesystem, for writing.
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140 |
Delete from map m the entry having key k.
Explain what happens if k is not an existing key in m. |
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141 |
Iterate in sequence over the elements of the list items1 then items2. For each iteration print the element.
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142 |
Assign to string s the hexadecimal representation (base 16) of integer x.
E.g. 999 -> "3e7" |
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143 |
Iterate alternatively over the elements of the lists items1 and items2. For each iteration, print the element.
Explain what happens if items1 and items2 have different size. |
Alternative implementation:
Alternative implementation:
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144 |
Set boolean b to true if file at path fp exists on filesystem; false otherwise.
Beware that you should not do this and then in the next instruction assume the result is still valid, this is a race condition on any multitasking OS. |
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145 |
Print message msg, prepended by current date and time.
Explain what behavior is idiomatic: to stdout or stderr, and what the date format is. |
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146 |
Extract floating point value f from its string representation s
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147 |
Create string t from string s, keeping only ASCII characters
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Alternative implementation:
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148 |
Read a list of integer numbers from the standard input, until EOF.
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Alternative implementation:
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149 |
As an exception, this content is not under license CC BY-SA 3.0 like the rest of this website.
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150 |
Remove the last character from the string p, if this character is a forward slash /
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Alternative implementation:
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151 |
Remove last character from string p, if this character is the file path separator of current platform.
Note that this also transforms unix root path "/" into the empty string! |
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152 |
Create string s containing only the character c.
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153 |
Create the string t as the concatenation of the string s and the integer i.
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154 |
Find color c, the average between colors c1, c2.
c, c1, c2 are strings of hex color codes: 7 chars, beginning with a number sign # . Assume linear computations, ignore gamma corrections. |
Alternative implementation:
Alternative implementation:
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155 |
Delete from filesystem the file having path filepath.
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156 |
Assign to the string s the value of the integer i in 3 decimal digits. Pad with zeros if i < 100. Keep all digits if i ≥ 1000.
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Alternative implementation:
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157 |
Initialize a constant planet with string value "Earth".
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158 |
Create a new list y from randomly picking exactly k elements from list x.
It is assumed that x has at least k elements. Each element must have same probability to be picked. Each element from x must be picked at most once. Explain if the original ordering is preserved or not. |
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160 |
Execute f32() if platform is 32-bit, or f64() if platform is 64-bit.
This can be either a compile-time condition (depending on target) or a runtime detection. |
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161 |
Multiply all the elements of the list elements by a constant c
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162 |
execute bat if b is a program option and fox if f is a program option.
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Alternative implementation:
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163 |
Print all the list elements, two by two, assuming list length is even.
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165 |
Assign to the variable x the last element of the list items.
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166 |
Create the list ab containing all the elements of the list a, followed by all the elements of the list b.
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167 |
Create the string t consisting of the string s with its prefix p removed (if s starts with p).
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Alternative implementation:
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168 |
Create string t consisting of string s with its suffix w removed (if s ends with w).
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Alternative implementation:
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169 |
Assign to the integer n the number of characters of the string s.
Make sure that multibyte characters are properly handled. n can be different from the number of bytes of s. |
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170 |
Set n to the number of elements stored in mymap.
This is not always equal to the map capacity. |
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171 |
Append the element x to the list s.
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172 |
Insert value v for key k in map m.
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173 |
Number will be formatted with a comma separator between every group of thousands.
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Alternative implementation:
Alternative implementation:
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174 |
Make a HTTP request with method POST to the URL u
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175 |
From the array a of n bytes, build the equivalent hex string s of 2n digits.
Each byte (256 possible values) is encoded as two hexadecimal characters (16 possible values per digit). |
Alternative implementation:
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176 |
From hex string s of 2n digits, build the equivalent array a of n bytes.
Each pair of hexadecimal characters (16 possible values per digit) is decoded into one byte (256 possible values). |
Alternative implementation:
Alternative implementation:
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177 |
Construct a list L that contains all filenames that have the extension ".jpg" , ".jpeg" or ".png" in directory D and all its subdirectories.
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178 |
Set boolean b to true if if the point with coordinates (x,y) is inside the rectangle with coordinates (x1,y1,x2,y2) , or to false otherwise.
Describe if the edges are considered to be inside the rectangle. |
Alternative implementation:
Alternative implementation:
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179 |
Return the center c of the rectangle with coördinates(x1,y1,x2,y2)
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Alternative implementation:
Alternative implementation:
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180 |
Create the list x containing the contents of the directory d.
x may contain files and subfolders. No recursive subfolder listing. |
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184 |
Assign to t a string representing the day, month and year of the day after the current date.
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185 |
Schedule the execution of f(42) in 30 seconds.
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Alternative implementation:
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186 |
Exit a program cleanly indicating no error to OS
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187 |
Disjoint Sets hold elements that are partitioned into a number of disjoint (non-overlapping) sets.
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189 |
Produce a new list y containing the result of the function T applied to all elements e of the list x that match the predicate P.
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191 |
Given a one-dimensional array a, check if any value is larger than x, and execute the procedure f if that is the case
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192 |
Declare a real variable a with at least 20 digits; if the type does not exist, issue an error at compile time.
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193 |
Declare two two-dimensional arrays a and b of dimension n*m and m*n, respectively. Assign to b the transpose of a (i.e. the value with index interchange).
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195 |
Pass an array a of real numbers to the procedure (resp. function) foo. Output the size of the array, and the sum of all its elements when each element is multiplied with the array indices i and j (assuming they start from one).
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196 |
Given an integer array a of size n, pass the first, third, fifth and seventh, ... up to the m th element to a routine foo which sets all these elements to 42.
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197 |
Retrieve the contents of file at path into a list of strings lines, in which each element is a line of the file.
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