1460. Make Two Arrays Equal by Reversing Subarrays

Problem Link

Description

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You are given two integer arrays of equal length target and arr. In one step, you can select any non-empty subarray 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 subarray [2,4,1], arr becomes [1,4,2,3]
2- Reverse subarray [4,2], arr becomes [1,2,4,3]
3- Reverse subarray [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 = [3,7,9], arr = [3,7,11]
Output: false
Explanation: arr does not have value 9 and it can never be converted to target.

 

Constraints:

• target.length == arr.length
• 1 <= target.length <= 1000
• 1 <= target[i] <= 1000
• 1 <= arr[i] <= 1000

Solution

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C++

class Solution {
public:
    bool canBeEqual(vector<int>& target, vector<int>& arr) {
        unordered_map<int, int> cnt;
        for (auto& x: target) ++cnt[x];
 
        for (auto& x: arr) if (--cnt[x] < 0) return false;
 
        return true;
    }
};

Python3

class Solution:
    def canBeEqual(self, target: List[int], arr: List[int]) -> bool:
        return Counter(target) == Counter(arr)