Merge branch 'youngyangyang04:master' into master

problems/0701.二叉搜索树中的插入操作.md

@@ -520,5 +520,71 @@ var insertIntoBST = function (root, val) {
 };
 ```
 
+## TypeScript
+
+> 递归-有返回值
+
+```typescript
+function insertIntoBST(root: TreeNode | null, val: number): TreeNode | null {
+    if (root === null) return new TreeNode(val);
+    if (root.val > val) {
+        root.left = insertIntoBST(root.left, val);
+    } else {
+        root.right = insertIntoBST(root.right, val);
+    }
+    return root;
+};
+```
+
+> 递归-无返回值
+
+```typescript
+function insertIntoBST(root: TreeNode | null, val: number): TreeNode | null {
+    if (root === null) return new TreeNode(val);
+    function recur(root: TreeNode | null, val: number) {
+        if (root === null) {
+            if (parentNode.val > val) {
+                parentNode.left = new TreeNode(val);
+            } else {
+                parentNode.right = new TreeNode(val);
+            }
+            return;
+        }
+        parentNode = root;
+        if (root.val > val) recur(root.left, val);
+        if (root.val < val) recur(root.right, val);
+    }
+    let parentNode: TreeNode = root;
+    recur(root, val);
+    return root;
+};
+```
+
+> 迭代法
+
+```typescript
+function insertIntoBST(root: TreeNode | null, val: number): TreeNode | null {
+    if (root === null) return new TreeNode(val);
+    let curNode: TreeNode | null = root;
+    let parentNode: TreeNode = root;
+    while (curNode !== null) {
+        parentNode = curNode;
+        if (curNode.val > val) {
+            curNode = curNode.left
+        } else {
+            curNode = curNode.right;
+        }
+    }
+    if (parentNode.val > val) {
+        parentNode.left = new TreeNode(val);
+    } else {
+        parentNode.right = new TreeNode(val);
+    }
+    return root;
+};
+```
+
+
+
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