Merge pull request kothariji#578 from alishaa561112/master

add binary tree maximum path sum

Author: kothariji

(LEETCODE) BinaryTreeMaximumPathSum.cpp

@@ -0,0 +1,33 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
+ * };
+ */
+class Solution {
+public:
+    int sum =  INT_MIN;
+    int findSum(TreeNode* root){
+        if(root==NULL)
+            return 0;
+
+        int ls = findSum(root->left);
+        int rs = findSum(root->right);
+        ls = max(ls,0);
+        rs = max(rs, 0);
+        int cs = ls + rs + root->val;
+        sum = max(sum, cs);
+
+        return max(ls, rs) + root->val;
+
+    }
+    int maxPathSum(TreeNode* root) {
+      findSum(root);
+        return sum;
+    }
+};

Tree/(LEETCODE) BinaryTreeMaximumPathSum.cpp

@@ -0,0 +1,33 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+ *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
+ * };
+ */
+class Solution {
+public:
+    int sum =  INT_MIN;
+    int findSum(TreeNode* root){
+        if(root==NULL)
+            return 0;
+
+        int ls = findSum(root->left);
+        int rs = findSum(root->right);
+        ls = max(ls,0);
+        rs = max(rs, 0);
+        int cs = ls + rs + root->val;
+        sum = max(sum, cs);
+
+        return max(ls, rs) + root->val;
+
+    }
+    int maxPathSum(TreeNode* root) {
+      findSum(root);
+        return sum;
+    }
+};