adds leetcode problem 1460. Make Two Arrays Equal by Reversing Sub-ar…

leetcode/array/MakeTwoArraysEqualByReversingSubarrays.java

@@ -0,0 +1,41 @@
+// 1460. Make Two Arrays Equal by Reversing Sub-arrays
+//You are 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 = [3,7,9], arr = [3,7,11]
+//Output: false
+//Explanation: arr does not have value 9 and it can never be converted to target.
+
+public class MakeTwoArraysEqualByReversingSubarrays {
+    public boolean canBeEqual(int[] target, int[] arr) {
+        if(target.length != arr.length) return false;
+        Map<Integer, Integer> map = new HashMap<>();
+        for(int i = 0; i < target.length; i++){
+            map.put(target[i], map.getOrDefault(target[i], 0) + 1);
+        }
+        for(int i = 0; i < arr.length; i++){
+            if(map.containsKey(arr[i])){
+                map.put(arr[i], map.getOrDefault(arr[i], 0) - 1);
+                if(map.get(arr[i]) == 0) map.remove(arr[i]);
+            }
+        }
+        return map.size() == 0;
+    }
+}