add js solution for leetcode 102 111 and 112

Author: swiftwind0405

README.md

@@ -314,8 +314,8 @@
 |115|[Distinct Subsequences](https://leetcode.com/problems/distinct-subsequences/)| |Hard|
 |114|[Flatten Binary Tree to Linked List](https://leetcode.com/problems/flatten-binary-tree-to-linked-list/)| |Medium|
 |113|[Path Sum II](https://leetcode.com/problems/path-sum-ii/)| |Medium|
-|112|[Path Sum](https://leetcode.com/problems/path-sum/)| |Easy|
-|111|[Minimum Depth of Binary Tree](https://leetcode.com/problems/minimum-depth-of-binary-tree/)| |Easy|
+|112|[Path Sum](https://leetcode.com/problems/path-sum/)| [js](./algorithms/pathSum/pathSum.js) |Easy|
+|111|[Minimum Depth of Binary Tree](https://leetcode.com/problems/minimum-depth-of-binary-tree/)| [js](./algorithms/minimumDepthOfBinaryTree/minimumDepthOfBinaryTree.js) |Easy|
 |110|[Balanced Binary Tree](https://leetcode.com/problems/balanced-binary-tree/)| [java](./algorithms/balancedBinaryTree/Solution.java) |Easy|
 |109|[Convert Sorted List to Binary Search Tree](https://leetcode.com/problems/convert-sorted-list-to-binary-search-tree/)| |Medium|
 |108|[Convert Sorted Array to Binary Search Tree](https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/)| |Medium|
@@ -324,7 +324,7 @@
 |105|[Construct Binary Tree from Preorder and Inorder Traversal](https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/)| |Medium|
 |104|[Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/)| [js](./algorithms/maximumDepthOfBinaryTree/maximumDepthOfBinaryTree.js) |Easy|
 |103|[Binary Tree Zigzag Level Order Traversal](https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/)| |Medium|
-|102|[Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/)| |Easy|
+|102|[Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/)| [js](./algorithms/binaryTreeLevelOrderTraversal/binaryTreeLevelOrderTraversal.js) |Easy|
 |101|[Symmetric Tree](https://leetcode.com/problems/symmetric-tree/)| [java](./algorithms/sysmetricTree/Solution.java) |Easy|
 |100|[Same Tree](https://leetcode.com/problems/same-tree/)| [java](./algorithms/sameTree/Solution.java) |Easy|
 |99|[Recover Binary Search Tree](https://leetcode.com/problems/recover-binary-search-tree/)| |Hard|

algorithms/binaryTreeLevelOrderTraversal/binaryTreeLevelOrderTraversal.js

@@ -0,0 +1,16 @@
+var levelOrder = function(root) {
+    if (!root) return [];
+    const res = [];
+    const q = [[root, 0]];
+    while (q.length) {
+        const [n, level] = q.shift();
+        if (res[level]) {
+            res[level].push(n.val)
+        } else {
+            res[level] = [n.val];
+        }
+        if (n.left) q.push([n.left, level + 1]);
+        if (n.right) q.push([n.right, level + 1]);
+    }
+    return res;
+};

algorithms/minimumDepthOfBinaryTree/minimumDepthOfBinaryTree.js

@@ -0,0 +1,12 @@
+var minDepth = function(root) {
+    if (!root) return 0;
+    // 广度优先需要使用一个队列，同时额外再维护一个深度
+    const q = [[root, 1]];
+    while (q.length) {
+        const [n, deepth] = q.shift();
+        if (!n.left && !n.right) return deepth;
+        // console.log(n.val, deepth);
+        if (n.left) q.push([n.left, deepth + 1]);
+        if (n.right) q.push([n.right, deepth + 1]);
+    }
+};

algorithms/pathSum/pathSum.js

@@ -0,0 +1,15 @@
+var hasPathSum = function(root, sum) {
+    if(!root) return false;
+    let res = false;
+    const dfs = (node, s) => {
+        // console.log(node.val, s);
+        // 如果是叶子节点，且当前路径的和为sum，就证明找到一个符合要求的路径
+        if (!node.left && !node.right && s === sum) {
+            res = true;
+        }
+        if(node.left) dfs(node.left, s + node.left.val);
+        if(node.right) dfs(node.right, s + node.right.val);
+    };
+    dfs(root, root.val);
+    return res;
+};