Binary Tree Maximum Path Sum / 심화

Author: oh-chaeyeon

oh-chaeyeon/5주차_트리/Binary_Tree_Maximum_Path_Sum.js

@@ -0,0 +1,31 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number}
+ */
+var maxPathSum = function (root) {
+  let maxSum = -Infinity;
+
+  function dfs(node) {
+    if (!node) return 0;
+
+    const left = Math.max(dfs(node.left), 0);
+    const right = Math.max(dfs(node.right), 0);
+
+    const currentSum = node.val + left + right;
+
+    maxSum = Math.max(maxSum, currentSum);
+
+    return node.val + Math.max(left, right);
+  }
+
+  dfs(root);
+  return maxSum;
+};