# LeetCode 1460. Make Two Arrays Equal by Reversing Subarrays

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

The idea behind is to check if they are anagram.

Time Complexity: O(n). n = target.length.

Space: O(n).

AC Java:

 1 class Solution {
2     public boolean canBeEqual(int[] target, int[] arr) {
3         if(target.length != arr.length){
4             return false;
5         }
6
7         HashMap<Integer, Integer> hm = new HashMap<>();
8         for(int num : target){
9             hm.put(num, hm.getOrDefault(num, 0) + 1);
10         }
11
12         for(int num : arr){
13             if(!hm.containsKey(num) || hm.get(num) <= 0){
14                 return false;
15             }
16
17             hm.put(num, hm.get(num) - 1);
18         }
19
20         return true;
21     }
22 }

posted @ 2024-06-02 23:54  Dylan_Java_NYC  阅读(5)  评论(0编辑  收藏  举报