Added solution to 1601 Maximum Number of Achievable Transfer Requests (fishercoder1534#110)

coderaky · web-flow · commit dc6e90a86b6e · 2020-10-02T07:43:15.000-07:00
* Adding java solution file for 1601 question

Maximum Number of Achievable Transfer Requests

* Maximum Number of Achievable Transfer Requests

Added solution to this Problem
diff --git a/README.md b/README.md
@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ &#9733;
 
 |  #  |      Title     |   Solutions   | Video  | Difficulty  | Tag                   
 |-----|----------------|---------------|--------|-------------|-------------
+|1601|[Maximum Number of Achievable Transfer Requests](https://leetcode.com/problems/maximum-number-of-achievable-transfer-requests/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1601.java) ||Hard|Backtracking|
 |1598|[Crawler Log Folder](https://leetcode.com/problems/crawler-log-folder/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1598.java) ||Easy|Stack|
 |1592|[Rearrange Spaces Between Words](https://leetcode.com/problems/rearrange-spaces-between-words/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1592.java) ||Easy|String|
 |1588|[Sum of All Odd Length Subarrays](https://leetcode.com/problems/sum-of-all-odd-length-subarrays/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1588.java) ||Easy|Array|
diff --git a/src/main/java/com/fishercoder/solutions/_1601.java b/src/main/java/com/fishercoder/solutions/_1601.java
@@ -0,0 +1,29 @@
+class Solution {
+    int max = 0;
+    public int maximumRequests(int n, int[][] requests) {
+        helper(requests, 0, new int[n], 0);
+        return max;
+    }
+    
+    private void helper(int[][] requests, int index, int[] count, int num) {
+        // Traverse all n buildings to see if they are all 0. (means balanced)
+        if (index == requests.length) {
+            for (int i : count) {
+                if (0 != i) {
+                    return;
+                }
+            }
+            max = Math.max(max, num);
+            return;
+        }
+		// Choose this request
+        count[requests[index][0]]++;
+        count[requests[index][1]]--;
+        helper(requests, index + 1, count, num + 1);
+        count[requests[index][0]]--;
+        count[requests[index][1]]++;
+        
+		// Not Choose the request
+        helper(requests, index + 1, count, num);
+    }
+}
