feat: add typescript solution to lc problem: No.2074 (#616)

No.2074.Reverse Nodes in Even Length Groups

Author: zhaocchen

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;
+};
+```
+
 ### **...**
 
 ```

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;
+};
+```
+
 ### **...**
 
 ```

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;
+};