# Exercises

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Given an array of `int` values, return true if the group of `n` numbers at the start of the array is the same as the group of `n` numbers at...

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Say that a "clump" in an array is a series of 2 or more adjacent elements of the same value. Return the number of clumps in the given...

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Given an array, return an array that contains exactly the same numbers as the original array, but rearranged so that every 4 is...

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Given a string, does "xyz" appear in the middle of the string? To define middle, we'll say that the number of chars to the left and right...

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Given a string `str` and an `int n`, return a string made of the first `n` characters of the string, followed by the first `n - 1` characters of...

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Return an array that contains the exact same numbers as the given array, but rearranged so that all the even numbers come before all the...

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Given `n` >= 0, create an array with the pattern {1, 1, 2, 1, 2, 3, ... 1, 2, 3 .. `n`} (spaces added to show the grouping). Note that...

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Given a string of any length, return a new string where the last 2 chars, if present, are swapped, so "coding" yields "codign".

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Given a string, return `true` if "bad" appears starting at index 0 or 1 in the string, such as with "badxxx" or "xbadxx" but not "xxbadxx"....

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Return a version of the given string, where for every star (*) in the string the star and the character immediately to its left and the...

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Return `true` if somewhere in the array, there are three increasing adjacent numbers like .... 4, 5, 6, ... or 23, 24, 25.

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Given `start` and `end` integers, return a new array containing the sequence of integers from `start` up to but not including `end`, so `start` = 5...

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Return an array that is "left shifted" by one--so for an input of {6, 2, 5, 3}, the method returns {2, 5, 3, 6}. You may modify and...

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Given a non-empty array of `int`s, return a new array containing the elements from the original array that come after the last 4 in the...

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We'll say that an element in an array is "alone" if there are values before and after it, and those values are different from it. Return...

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Return an array that contains the exact same numbers as the given array, but rearranged so that all the zeros are grouped at the start of...

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Given two arrays of `int`s sorted in increasing order, called `outer` and `inner`, return `true` if all of the numbers in `inner` also appear in `...`

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Given `n` >= 0, create an array of length `n * n` with the following pattern, shown here for `n` = 3 : {0, 0, 1, 0, 2, 1, 3, 2, 1} (spaces...

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Given an `out` string of length 4, such as "<<>>", and a `word`, return a new string where the `word` is in the middle of the `out`...

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Given a string, return a new string made of 3 copies of the last 2 chars of the original string. The string's length will be at least 2.

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Given a string, return the string made of its first two chars, so the string "Hello" yields "He". If the string is shorter than length 2,...

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Return `true` if the string "cat" and "dog" appear the same number of times in the given string.

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Return true if the given string contains a "bob" string, but where the middle 'o' character can be any character.

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Given two strings, `word` and a separator `sep`, return a big string made of `count` occurrences of the `word`, separated by the separator...

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Given a string, count the number of words ending in 'y' or 'z'--so the 'y' in "heavy" and the 'z' in "fez" count, but not the 'y' in...