首页 > 代码库 > Swap Nodes in Pairs
Swap Nodes in Pairs
Given a linked list, swap every two adjacent nodes and return its head.
For example,
Given 1->2->3->4
, you should return the list as 2->1->4->3
.
Your algorithm should use only constant space. You may not modify the values in the list, only nodes itself can be changed.
C++实现代码:
#include<iostream>#include<new>using namespace std;//Definition for singly-linked list.struct ListNode{ int val; ListNode *next; ListNode(int x) : val(x), next(NULL) {}};class Solution{public: ListNode *swapPairs(ListNode *head) { if(head==NULL||head->next==NULL) return head; ListNode *p=head; ListNode *pre=head; ListNode *qq=NULL; ListNode *q=NULL; while(p&&p->next) { q=p->next; p->next=NULL; qq=q->next; q->next=NULL; q->next=p; p->next=qq; if(p==head) { head=q; } else pre->next=q; pre=p; p=p->next; } return head; } void createList(ListNode *&head) { ListNode *p=NULL; int i=0; int arr[10]= {7,5,6,4,1,3,9,8,2,10}; for(i=0; i<2; i++) { if(head==NULL) { head=new ListNode(arr[i]); if(head==NULL) return; } else { p=new ListNode(arr[i]); p->next=head; head=p; } } }};int main(){ Solution s; ListNode *L=NULL; s.createList(L); ListNode *head=L; while(head) { cout<<head->val<<" "; head=head->next; } cout<<endl; L=s.swapPairs(L); while(L) { cout<<L->val<<" "; L=L->next; }}
运行结果:
Swap Nodes in Pairs
声明:以上内容来自用户投稿及互联网公开渠道收集整理发布,本网站不拥有所有权,未作人工编辑处理,也不承担相关法律责任,若内容有误或涉及侵权可进行投诉: 投诉/举报 工作人员会在5个工作日内联系你,一经查实,本站将立刻删除涉嫌侵权内容。