Merge pull request #1849 from tahsintunan/112

Create 112. Path Sum

Author: tahsintunan

Diff for: go/0112-path-sum.go

@@ -0,0 +1,25 @@
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+
+func hasPathSum(root *TreeNode, targetSum int) bool {
+	if root == nil {
+		return false
+	}
+	if isChild(root) && targetSum == root.Val {
+		return true
+	}
+	if hasPathSum(root.Left, targetSum-root.Val) || hasPathSum(root.Right, targetSum-root.Val) {
+		return true
+	}
+	return false
+}
+
+func isChild(node *TreeNode) bool {
+	return node.Left == nil && node.Right == nil
+}