Merge pull request #5 from Mohitkumar6122/patch-5

Create 241.cpp

Author: Visualstudio12

LeetCode/241.cpp

@@ -0,0 +1,40 @@
+class Solution {
+    unordered_map<string, vector<int>> ma ;
+public:
+    vector<int> diffWaysToCompute(string expression) {
+        int n = expression.size() ;
+        vector<int> ans ;
+        
+        for(int i = 0; i < n; ++i){
+            char c = expression[i] ;
+            if (c == '*' || c == '+' || c == '-'){
+                vector<int> n1, n2 ;
+                string s1 = expression.substr(0, i), s2 = expression.substr(i + 1) ;
+                // cout << s1 << " " << s2 ;
+                
+                n1 = (ma.find(s1) != ma.end()) ? ma[s1] : diffWaysToCompute(s1) ;
+                n2 = (ma.find(s2) != ma.end()) ? ma[s2] : diffWaysToCompute(s2) ;
+                
+                
+                for(auto x : n1){
+                    for(auto y : n2){
+                        if (c == '-') ans.push_back(x - y) ;
+                        else if (c == '+') ans.push_back(x + y) ;
+                        else ans.push_back(x * y) ;
+                    }
+                }
+            }
+        }
+        if(ans.empty()) ans.push_back(stoi(expression)) ;
+        ma[expression] = ans ;
+        return ans ;
+     
+    }
+};
+/*
+Input: expression = "2-1-1"
+Output: [0,2]
+Explanation:
+((2-1)-1) = 0 
+(2-(1-1)) = 2
+*/