add LeetCode 112

Author: ytlm

c/LeetCode/112.path-sum.c

@@ -0,0 +1,31 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     struct TreeNode *left;
+ *     struct TreeNode *right;
+ * };
+ */
+
+
+bool hasPathSum(struct TreeNode* root, int sum){
+
+    if (root == NULL) {
+        return 0;
+    }
+
+    if (!root->left && !root->right) {
+        return sum == root->val;
+    }
+
+    if (!root->left && root->right) {
+        return hasPathSum(root->right, sum - root->val);
+    }
+
+    if (root->left && !root->right) {
+        return hasPathSum(root->left, sum - root->val);
+    }
+
+    return hasPathSum(root->left, sum - root->val) || hasPathSum(root->right, sum - root->val);
+}
+