feat: add typescript solution to lc problem: No.0114.Flatten Binary Tree to Linked List (doocs#456)

zhaocchen · web-flow · commit b079007d7950 · 2021-06-16T11:53:12.000+08:00
diff --git a/solution/0100-0199/0114.Flatten Binary Tree to Linked List/README.md b/solution/0100-0199/0114.Flatten Binary Tree to Linked List/README.md
@@ -126,6 +126,42 @@ class Solution {
 }
 ```
 
+### **TypeScript**
+
+```ts
+/**
+ * Definition for a binary tree node.
+ * class TreeNode {
+ *     val: number
+ *     left: TreeNode | null
+ *     right: TreeNode | null
+ *     constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.left = (left===undefined ? null : left)
+ *         this.right = (right===undefined ? null : right)
+ *     }
+ * }
+ */
+
+/**
+ Do not return anything, modify root in-place instead.
+ */
+function flatten(root: TreeNode | null): void {
+    while (root != null) {
+        if (root.left != null) {
+            let pre = root.left;
+            while (pre.right != null) {
+                pre = pre.right;
+            }
+            pre.right = root.right;
+            root.right = root.left;
+            root.left = null;
+        }
+        root = root.right;
+    }
+};
+```
+
 ### **C++**
 
 ```cpp
diff --git a/solution/0100-0199/0114.Flatten Binary Tree to Linked List/README_EN.md b/solution/0100-0199/0114.Flatten Binary Tree to Linked List/README_EN.md
@@ -109,6 +109,42 @@ class Solution {
 }
 ```
 
+### **TypeScript**
+
+```ts
+/**
+ * Definition for a binary tree node.
+ * class TreeNode {
+ *     val: number
+ *     left: TreeNode | null
+ *     right: TreeNode | null
+ *     constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.left = (left===undefined ? null : left)
+ *         this.right = (right===undefined ? null : right)
+ *     }
+ * }
+ */
+
+/**
+ Do not return anything, modify root in-place instead.
+ */
+function flatten(root: TreeNode | null): void {
+    while (root != null) {
+        if (root.left != null) {
+            let pre = root.left;
+            while (pre.right != null) {
+                pre = pre.right;
+            }
+            pre.right = root.right;
+            root.right = root.left;
+            root.left = null;
+        }
+        root = root.right;
+    }
+};
+```
+
 ### **C++**
 
 ```cpp
diff --git a/solution/0100-0199/0114.Flatten Binary Tree to Linked List/Solution.ts b/solution/0100-0199/0114.Flatten Binary Tree to Linked List/Solution.ts
@@ -0,0 +1,31 @@
+/**
+ * Definition for a binary tree node.
+ * class TreeNode {
+ *     val: number
+ *     left: TreeNode | null
+ *     right: TreeNode | null
+ *     constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.left = (left===undefined ? null : left)
+ *         this.right = (right===undefined ? null : right)
+ *     }
+ * }
+ */
+
+/**
+ Do not return anything, modify root in-place instead.
+ */
+ function flatten(root: TreeNode | null): void {
+    while (root != null) {
+        if (root.left != null) {
+            let pre = root.left;
+            while (pre.right != null) {
+                pre = pre.right;
+            }
+            pre.right = root.right;
+            root.right = root.left;
+            root.left = null;
+        }
+        root = root.right;
+    }
+};
