1460

1460. Make Two Arrays Equal by Reversing Sub-arrays (Easy)

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

Related Topics:
Array

Solution 1.

// OJ: https://leetcode.com/problems/make-two-arrays-equal-by-reversing-sub-arrays/
// Author: github.com/lzl124631x
// Time: O(N)
// Space: O(N)
class Solution {
public:
    bool canBeEqual(vector<int>& B, vector<int>& A) {
        unordered_map<int, int> cnt;
        for (int n : A) cnt[n]++;
        for (int n : B) {
            if (--cnt[n] < 0) return false;
        }
        return true;
    }
};

Solution 2.

// OJ: https://leetcode.com/problems/make-two-arrays-equal-by-reversing-sub-arrays/
// Author: github.com/lzl124631x
// Time: O(NlogN)
// Space: O(1)
class Solution {
public:
    bool canBeEqual(vector<int>& A, vector<int>& B) {
        sort(begin(A), end(A));
        sort(begin(B), end(B));
        return A == B;
    }
};