// Source : https://leetcode.com/problems/make-two-arrays-equal-by-reversing-sub-arrays/ // Author : Hao Chen // Date : 2020-10-02 /***************************************************************************************************** * * Given two integer arrays of equal length target and arr. * * In one step, you can select any non-empty sub-array of arr and reverse it. You are allowed to make * any number of steps. * * Return True if you can make arr equal to target, or False otherwise. * * Example 1: * * Input: target = [1,2,3,4], arr = [2,4,1,3] * Output: true * Explanation: You can follow the next steps to convert arr to target: * 1- Reverse sub-array [2,4,1], arr becomes [1,4,2,3] * 2- Reverse sub-array [4,2], arr becomes [1,2,4,3] * 3- Reverse sub-array [4,3], arr becomes [1,2,3,4] * There are multiple ways to convert arr to target, this is not the only way to do so. * * Example 2: * * Input: target = [7], arr = [7] * Output: true * Explanation: arr is equal to target without any reverses. * * Example 3: * * Input: target = [1,12], arr = [12,1] * Output: true * * Example 4: * * Input: target = [3,7,9], arr = [3,7,11] * Output: false * Explanation: arr doesn't have value 9 and it can never be converted to target. * * Example 5: * * Input: target = [1,1,1,1,1], arr = [1,1,1,1,1] * Output: true * * Constraints: * * target.length == arr.length * 1 <= target.length <= 1000 * 1 <= target[i] <= 1000 * 1 <= arr[i] <= 1000 ******************************************************************************************************/ class Solution { public: // This problem could transfer to check two array has exactly same numbers bool canBeEqual(vector& target, vector& arr) { int len1 = target.size(); int len2 = arr.size(); if (len1 != len2) return false; if (len1 == 0) return true; unordered_map stat; for (int i=0; i