算法.链表反转

来源：互联网发布：linux 自动化测试编辑：程序博客网时间：2024/06/05 10:14

链表反转的思路：

lrs.h:

/*************************************************************************        > File Name: lrs.h        > Author: zhoulin        > Mail: 715169549@qq.com        > Created Time: Sun 17 Apr 2016 01:08:11 PM CST ************************************************************************/#ifndef _LRS_H#define _LRS_Htypedef struct _listNode{    int v;    struct _listNode *next;}listNode;//reverse a list node start with start,end whith end postionlistNode *listReverse(listNode *p,int start,int end);#endif

lrs.c:

/*************************************************************************        > File Name: lrs.c        > Author: zhoulin        > Mail: 715169549@qq.com        > Created Time: Sun 17 Apr 2016 01:09:37 PM CST ************************************************************************/#include "lrs.h"#include <stdio.h>void listPrt(listNode *p){    while(p != NULL)    {        if(p->next == NULL)        {            fprintf(stdout,"%d\n",p->v);            break;        }        fprintf(stdout,"%d ->",p->v);        p = p->next;    }}/* *采用分治法 * 1.拆分链为2个链表，t_head保存目标链表的头节点，t_tail保存目标链表的最后一个节点 * 2.cur遍历到t_tail的下一个节点，n_head为t_tail下一个节点开始的新链表，采用头插法把cur节点插入到新链表，依次循环 * 3.t_tail的下一个节点为新链表的头节点，t_tail->next = n_head;最后把n_tail指向cur遍历的剩余节点。 */listNode *listReverse(listNode *p,int start,int end){    if(start >= end)    {        return p;    }    listNode *t_head,*t_tail;//target_head为目标链表第一节点，target_cur为目标链表的最后一个节点    listNode *cur,*n_head,*n_tail;//cur为遍历p的游标节点    cur = n_head = n_tail =NULL;    t_head = t_tail = NULL;    int i = 1;    for(;i <start;i++)    {        if(i == 1)        {            t_head = p;        }        if(i == start -1)        {            t_tail = p;        }        p = p->next;//find list head next node    }    cur = p;    for(;(i <= end)&& (cur != NULL);i++)    {        listNode *pn = cur->next;        if(n_head == NULL)        {            n_head = n_tail = cur;        }else{            cur->next = n_head;            n_head = cur;        }        cur = pn;    }    if(t_head == NULL)    {        t_head = n_head;        t_tail = n_tail;    }else{        t_tail->next = n_head;    }    if(n_tail != NULL)        n_tail->next = cur;    return t_head;}int main(void){    int i,j;    for(i = 6;i>=1;i--)    {        for(j=1;j<=i;j++)        {            if(j>=i)            {                continue;            }            listNode a1,a2,a3,a4,a5,a6;            a1.v =1;            a2.v =2;            a3.v =3;            a4.v =4;            a5.v =5;            a6.v =6;            a1.next = &a2;            a2.next = &a3;            a3.next = &a4;            a4.next = &a5;            a5.next = &a6;            a6.next = NULL;            listNode *tmp = &a1;            fprintf(stdout,"------------------------source list----------------------------\n");            listPrt(tmp);            fprintf(stdout,"------------------------listReverse(%d,%d)---------------------\n",j,i);            listNode *rs = listReverse(tmp,j,i);            if(rs != NULL)                listPrt(rs);                fprintf(stdout,"\n");        }    }    return 0;}

运行结果:

root@:/data/code/cwork/demo:./lrs------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(1,6)---------------------6 ->5 ->4 ->3 ->2 ->1------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(2,6)---------------------1 ->6 ->5 ->4 ->3 ->2------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(3,6)---------------------1 ->2 ->6 ->5 ->4 ->3------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(4,6)---------------------1 ->2 ->3 ->6 ->5 ->4------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(5,6)---------------------1 ->2 ->3 ->4 ->6 ->5------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(1,5)---------------------5 ->4 ->3 ->2 ->1 ->6------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(2,5)---------------------1 ->5 ->4 ->3 ->2 ->6------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(3,5)---------------------1 ->2 ->5 ->4 ->3 ->6------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(4,5)---------------------1 ->2 ->3 ->5 ->4 ->6------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(1,4)---------------------4 ->3 ->2 ->1 ->5 ->6------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(2,4)---------------------1 ->4 ->3 ->2 ->5 ->6------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(3,4)---------------------1 ->2 ->4 ->3 ->5 ->6------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(1,3)---------------------3 ->2 ->1 ->4 ->5 ->6------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(2,3)---------------------1 ->3 ->2 ->4 ->5 ->6------------------------source list----------------------------1 ->2 ->3 ->4 ->5 ->6------------------------listReverse(1,2)---------------------2 ->1 ->3 ->4 ->5 ->6

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