113. Path Sum 2

Author: SjxSubham

113. Path Sum 2

@@ -0,0 +1,36 @@
+void solve(TreeNode* root,int targetSum,int &currsum,vector<int>&path,  vector<vector<int>>&ans){
+    if(root == NULL){
+        return;
+    }
+    //leaf node
+    if(root->left == NULL && root->right == NULL){
+        path.push_back(root->val);
+        currsum += root->val;
+        if(currsum == targetSum){
+            ans.push_back(path);
+        }
+        //exceptional
+        path.pop_back();
+        currsum -= root->val;
+        return;
+    }
+    //include curr node
+    path.push_back(root->val);
+    currsum += root->val;
+
+    solve(root->left,targetSum,currsum,path,ans);
+    solve(root->right,targetSum,currsum,path,ans);
+
+    //exceptional backtrack, aslo can be done without this
+    path.pop_back();
+    currsum -= root->val;
+
+}
+    vector<vector<int>> pathSum(TreeNode* root, int targetSum) {
+         vector<vector<int>>ans;
+         int sum =0;
+         vector<int>path;
+         solve(root,targetSum, sum ,path,ans);
+         return ans;
+
+    }