From cf550bac73c8fa200d682e361cc619f96f0bbd2d Mon Sep 17 00:00:00 2001
From: zhaocchen <zhaocchen@163.com>
Date: Wed, 17 Nov 2021 15:16:30 +0800
Subject: [PATCH] feat: add typescript solution to lc problem: No.2074.Reverse
 Nodes in Even Length Groups

---
 .../README.md                                 | 43 +++++++++++++++++++
 .../README_EN.md                              | 43 +++++++++++++++++++
 .../Solution.ts                               | 38 ++++++++++++++++
 3 files changed, 124 insertions(+)
 create mode 100644 solution/2000-2099/2074.Reverse Nodes in Even Length Groups/Solution.ts

diff --git a/solution/2000-2099/2074.Reverse Nodes in Even Length Groups/README.md b/solution/2000-2099/2074.Reverse Nodes in Even Length Groups/README.md
index 799313676c475..e5e53c6e4e08f 100644
--- a/solution/2000-2099/2074.Reverse Nodes in Even Length Groups/README.md	
+++ b/solution/2000-2099/2074.Reverse Nodes in Even Length Groups/README.md	
@@ -190,6 +190,49 @@ class Solution {
 }
 ```
 
+### **TypeScript**
+
+```ts
+/**
+ * Definition for singly-linked list.
+ * class ListNode {
+ *     val: number
+ *     next: ListNode | null
+ *     constructor(val?: number, next?: ListNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.next = (next===undefined ? null : next)
+ *     }
+ * }
+ */
+
+function reverseEvenLengthGroups(head: ListNode | null): ListNode | null {
+    let nums = [];
+    let cur = head;
+    while (cur) {
+        nums.push(cur.val);
+        cur = cur.next;
+    }
+
+    const n = nums.length;
+    for (let i = 0, k = 1; i < n; i += k, k++) {
+        // 最后一组， 可能出现不足
+        k = Math.min(n - i, k);
+        if (!(k & 1)) {
+            let tmp = nums.splice(i, k);
+            tmp.reverse();
+            nums.splice(i, 0, ...tmp);
+        }
+    }
+
+    cur = head;
+    for (let num of nums) {
+        cur.val = num;
+        cur = cur.next;
+    }
+    return head;
+};
+```
+
 ### **...**
 
 ```
diff --git a/solution/2000-2099/2074.Reverse Nodes in Even Length Groups/README_EN.md b/solution/2000-2099/2074.Reverse Nodes in Even Length Groups/README_EN.md
index 491d425f6d6fb..d4b78d3fe4f47 100644
--- a/solution/2000-2099/2074.Reverse Nodes in Even Length Groups/README_EN.md	
+++ b/solution/2000-2099/2074.Reverse Nodes in Even Length Groups/README_EN.md	
@@ -174,6 +174,49 @@ class Solution {
 }
 ```
 
+### **TypeScript**
+
+```ts
+/**
+ * Definition for singly-linked list.
+ * class ListNode {
+ *     val: number
+ *     next: ListNode | null
+ *     constructor(val?: number, next?: ListNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.next = (next===undefined ? null : next)
+ *     }
+ * }
+ */
+
+function reverseEvenLengthGroups(head: ListNode | null): ListNode | null {
+    let nums = [];
+    let cur = head;
+    while (cur) {
+        nums.push(cur.val);
+        cur = cur.next;
+    }
+
+    const n = nums.length;
+    for (let i = 0, k = 1; i < n; i += k, k++) {
+        // 最后一组， 可能出现不足
+        k = Math.min(n - i, k);
+        if (!(k & 1)) {
+            let tmp = nums.splice(i, k);
+            tmp.reverse();
+            nums.splice(i, 0, ...tmp);
+        }
+    }
+
+    cur = head;
+    for (let num of nums) {
+        cur.val = num;
+        cur = cur.next;
+    }
+    return head;
+};
+```
+
 ### **...**
 
 ```
diff --git a/solution/2000-2099/2074.Reverse Nodes in Even Length Groups/Solution.ts b/solution/2000-2099/2074.Reverse Nodes in Even Length Groups/Solution.ts
new file mode 100644
index 0000000000000..102cb44da0b7b
--- /dev/null
+++ b/solution/2000-2099/2074.Reverse Nodes in Even Length Groups/Solution.ts	
@@ -0,0 +1,38 @@
+/**
+ * Definition for singly-linked list.
+ * class ListNode {
+ *     val: number
+ *     next: ListNode | null
+ *     constructor(val?: number, next?: ListNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.next = (next===undefined ? null : next)
+ *     }
+ * }
+ */
+
+ function reverseEvenLengthGroups(head: ListNode | null): ListNode | null {
+    let nums = [];
+    let cur = head;
+    while (cur) {
+        nums.push(cur.val);
+        cur = cur.next;
+    }
+
+    const n = nums.length;
+    for (let i = 0, k = 1; i < n; i += k, k++) {
+        // 最后一组， 可能出现不足
+        k = Math.min(n - i, k);
+        if (!(k & 1)) {
+            let tmp = nums.splice(i, k);
+            tmp.reverse();
+            nums.splice(i, 0, ...tmp);
+        }
+    }
+
+    cur = head;
+    for (let num of nums) {
+        cur.val = num;
+        cur = cur.next;
+    }
+    return head;
+};
\ No newline at end of file