diff --git a/problems/0206.翻转链表.md b/problems/0206.翻转链表.md index 13ed753c..941928ba 100644 --- a/problems/0206.翻转链表.md +++ b/problems/0206.翻转链表.md @@ -314,6 +314,54 @@ var reverseList = function(head) { }; ``` +TypeScript: + +```typescript +// 双指针法 +function reverseList(head: ListNode | null): ListNode | null { + let preNode: ListNode | null = null, + curNode: ListNode | null = head, + tempNode: ListNode | null; + while (curNode) { + tempNode = curNode.next; + curNode.next = preNode; + preNode = curNode; + curNode = tempNode; + } + return preNode; +}; + +// 递归(从前往后翻转) +function reverseList(head: ListNode | null): ListNode | null { + function recur(preNode: ListNode | null, curNode: ListNode | null): ListNode | null { + if (curNode === null) return preNode; + let tempNode: ListNode | null = curNode.next; + curNode.next = preNode; + preNode = curNode; + curNode = tempNode; + return recur(preNode, curNode); + } + return recur(null, head); +}; + +// 递归(从后往前翻转) +function reverseList(head: ListNode | null): ListNode | null { + if (head === null) return null; + let newHead: ListNode | null; + function recur(node: ListNode | null, preNode: ListNode | null): void { + if (node.next === null) { + newHead = node; + newHead.next = preNode; + } else { + recur(node.next, node); + node.next = preNode; + } + } + recur(head, null); + return newHead; +}; +``` + Ruby: ```ruby