Create Matchsticks to Square.cpp

Author: wargraver

Leetcode/Dynamic Programming/Matchsticks to Square.cpp

@@ -0,0 +1,22 @@
+typedef long long ll;
+class Solution {
+public:
+    bool ways(vector<int> match,ll i,ll s1,ll s2,ll s3,ll s4){
+        if(s1==0 && s2==0 && s3==0 && s4==0 && i==match.size()) return true;
+        else if(i>=match.size()) return false;
+        else if(s1<0 || s2<0 || s3<0 || s4<0) return false;
+        else{
+return (ways(match,i+1,s1-match[i],s2,s3,s4) or ways(match,i+1,s1,s2-match[i],s3,s4) or ways(match,i+1,s1,s2,s3-match[i],s4) or ways(match,i+1,s1,s2,s3,s4-match[i]));
+        }
+    }
+    bool makesquare(vector<int>& match) {
+      ll i,j,k,n,m,ct=0,sum=0;
+        n= match.size();
+        for(i=0;i<n;i++) sum += match[i];
+        if(sum%4==0){
+            ll sidelength = sum/4;
+            return ways(match,0,sidelength,sidelength,sidelength,sidelength);
+        }
+        else return false;
+    }
+};