Runtime: 3 ms (Top 98.54%) | Memory: 42 MB (Top 43.12%)

Author: AnasImloul

scripts/algorithms/M/Matchsticks to Square/Matchsticks to Square.java

@@ -1,7 +1,8 @@
+// Runtime: 3 ms (Top 98.54%) | Memory: 42 MB (Top 43.12%)
 /*
     Time complexity: O(2 ^ n)
     Space complexity: O(n)
-    
+
     Inutition:
     ---------
     Same as "Partition to K Equal Sum Subsets"
@@ -16,55 +17,55 @@ public boolean backtrack(int[] nums, int idx, int k, int subsetSum, int target,
             // if one of the side is found then keep finding the other k - 1 sides starting again from the beginning
             return backtrack(nums, 0, k - 1, 0, target, vis);
         }
-        
+
         // hypothesis
         for(int i = idx; i < nums.length; i++) {
             // if number is already visited or sum if out of range then skip
             if (vis[i] || subsetSum + nums[i] > target)
                 continue;
-            
+
             // Pruning
-            // if the last position (i - 1) is not visited, that means the current combination didn't work, 
+            // if the last position (i - 1) is not visited, that means the current combination didn't work,
             // and since this position (i) has the same value, it won't work for it as well. Thus, skip it.
-		    if (i - 1 >= 0 && nums[i] == nums[i - 1] && !vis[i - 1]) 
+            if (i - 1 >= 0 && nums[i] == nums[i - 1] && !vis[i - 1])
                 continue;
-            
+
             vis[i] = true;
             if (backtrack(nums, i + 1, k, subsetSum + nums[i], target, vis))
                 return true;
-                
+
             // backtrack
             vis[i] = false;
         }
-        
+
         return false;
     }
-    
+
     private void reverse(int[] arr) {
         for (int i = 0, j = arr.length - 1; i < j; i++, j--) {
             int tmp = arr[i];
             arr[i] = arr[j];
             arr[j] = tmp;
         }
     }
-    
+
     public boolean makesquare(int[] matchsticks) {
         int sum = 0;
         int k = 4;
         int n = matchsticks.length;
-        // sort the array in descending order to make the recursion hit the base case quicker 
+        // sort the array in descending order to make the recursion hit the base case quicker
         Arrays.sort(matchsticks);
         reverse(matchsticks);
-        
+
         for(int match: matchsticks)
             sum += match;
-        
+
         if (sum % k != 0)
             return false;
-        
+
         int target = sum / k;
         boolean[] vis = new boolean[n];
-        
+
         return backtrack(matchsticks, 0, k, 0, target, vis);
     }
-}
+}