Check if two arrays are permutations of each other - GeeksQuiz

Check if two arrays are permutations of each other - GeeksQuiz

Given two unsorted arrays of same size, write a function that returns true if two arrays are permutations of each other, otherwise false.

Examples:

Input: arr1[] = {2, 1, 3, 5, 4, 3, 2}         arr2[] = {3, 2, 2, 4, 5, 3, 1}  Output: Yes    Input: arr1[] = {2, 1, 3, 5,}         arr2[] = {3, 2, 2, 4}  Output: No  

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A Simple Solution is sort both arrays and compare sorted arrays. Time complexity of this solution is O(nLogn)

A Better Solution is to use Hashing.
1) Create a Hash Map for all the elements of arr1[] such that array elements are keys and their counts are values.
2) Traverse arr2[] and search for each element of arr2[] in the Hash Map. If element is found then decrement its count in hash map. If not found, then return false.
3) If all elements are found then return true.

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