feat: add typescript solution to lc problem: No.0061.Rotate List (#446)

Author: zhaocchen

solution/0000-0099/0061.Rotate List/README.md

@@ -122,6 +122,48 @@ 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 rotateRight(head: ListNode | null, k: number): ListNode | null {
+    if (k == 0  || head == null || head.next == null) return head;
+    // mod n
+    let n = 0;
+    let p = head;
+    while (p != null) {
+        ++n;
+        p = p.next;
+    }
+    k %= n;
+    if (k == 0) return head;
+    
+    let fast = head, slow = head;
+    for (let i = 0; i < k; ++i) {
+        fast = fast.next;
+    }
+    while (fast.next != null) {
+        slow = slow.next;
+        fast = fast.next;
+    }
+    let start = slow.next;
+    slow.next = null;
+    fast.next = head;
+    return start;
+};
+```
+
 ### **C#**
 
 ```cs

solution/0000-0099/0061.Rotate List/README_EN.md

@@ -108,6 +108,48 @@ 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 rotateRight(head: ListNode | null, k: number): ListNode | null {
+    if (k == 0  || head == null || head.next == null) return head;
+    // mod n
+    let n = 0;
+    let p = head;
+    while (p != null) {
+        ++n;
+        p = p.next;
+    }
+    k %= n;
+    if (k == 0) return head;
+    
+    let fast = head, slow = head;
+    for (let i = 0; i < k; ++i) {
+        fast = fast.next;
+    }
+    while (fast.next != null) {
+        slow = slow.next;
+        fast = fast.next;
+    }
+    let start = slow.next;
+    slow.next = null;
+    fast.next = head;
+    return start;
+};
+```
+
 ### **C#**
 
 ```cs

solution/0000-0099/0061.Rotate List/Soution.ts

@@ -0,0 +1,37 @@
+/**
+ * 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 rotateRight(head: ListNode | null, k: number): ListNode | null {
+    if (k == 0  || head == null || head.next == null) return head;
+    // mod n
+    let n = 0;
+    let p = head;
+    while (p != null) {
+        ++n;
+        p = p.next;
+    }
+    k %= n;
+    if (k == 0) return head;
+    
+    let fast = head, slow = head;
+    for (let i = 0; i < k; ++i) {
+        fast = fast.next;
+    }
+    while (fast.next != null) {
+        slow = slow.next;
+        fast = fast.next;
+    }
+    let start = slow.next;
+    slow.next = null;
+    fast.next = head;
+    return start;
+};