list的常见操作以及算法的时间复杂度
链表操作,时间复杂度为O(n),重在思维和设计,如下给出了一个链表的常见操作的实例
(1) 维护一个数组,来标记链表的元素是否存在
(2)数组下标和值得反应反映射,例如 a ={10,20,30,20}
t[256] = {-1}
t[10] =1;t[20] =1;t[30] =1;
a数组的最后一个元素为20,t[20]已经为1,记录20存在元素的个数,t[20]++;即可
/************************************************************************* > File Name: list_op.h > Author: zhoulin > Mail: 715169549@qq.com > Created Time: Sat 23 Apr 2016 09:23:40 AM CST ************************************************************************/ #ifndef _LIST_OP_H #define listSize 256 #include <pthread.h> typedef struct _listNode { int v; struct _listNode *next; }listNode; typedef struct _listMgr { unsigned int len; int vmax; int vmin; struct _listNode *head; int flag[listSize]; pthread_mutex_t lock; }listMgr; #define listMgrInit(mgr,max) \ { \ mgr->len = 0; \ mgr->vmax = max; \ mgr->vmin = max; \ mgr->head = NULL; \ memset(mgr->flag,-1,sizeof(int)*max); \ } #define rebuild(p,h,t) \ { \ if(h == NULL) \ { \ h = t = p; \ }else{ \ t->next = p; \ t = p; \ } \ t->next = NULL; \ } //打印链表,时间复杂度O(n) void listPrt(listNode *p); //链表初始化,时间负责度O(n) listNode *listInit(listMgr *mgr,listNode *a,int n,int max); //删除链表P中有过重复的元素 listNode *listDRepeat(listMgr *mgr); //删除链表中重复元素 listNode *listNRepeat(listMgr *mgr); //给定一个值,要求链表左边小于该值,链表右边大于该值,且链表的相对位置不改变 listNode *listQuick(listMgr *mgr,int v); //链表排序 listNode *listOrder(listMgr *mgr); #define _LIST_OP_H #endif
/************************************************************************* > File Name: list_op.c > Author: zhoulin > Mail: 715169549@qq.com > Created Time: Sat 23 Apr 2016 09:15:55 AM CST ************************************************************************/ #include "list_op.h" #include <stdio.h> #include <stdlib.h> #include <string.h> listNode *listQuick(listMgr *mgr,int v) { pthread_mutex_init(&mgr->lock,NULL); pthread_mutex_lock(&mgr->lock); fprintf(stdout,"**************************v=%d,大于v的节点在v节点右侧,否则在左侧*****************************\n",v); listNode *b_h,*b_t; listNode *s_h,*s_t; listNode *r_h,*r_t; int *flag = mgr->flag; if(flag[v] <= 0) { return mgr->head; } r_h = r_t = b_h = b_t = s_h = s_t=NULL; listNode *p = mgr->head; while(p != NULL) { listNode *pnext = p->next; if(p->v == v) { rebuild(p,r_h,r_t); } else if(p->v > v) { rebuild(p,b_h,b_t); }else{ rebuild(p,s_h,s_t); } p = pnext; } if(s_t != NULL) mgr->head = s_h; s_t->next = r_h; if(r_t != NULL) r_t->next = b_h; pthread_mutex_unlock(&mgr->lock); return mgr->head; } listNode *listNRepeat(listMgr *mgr) { pthread_mutex_init(&mgr->lock,NULL); pthread_mutex_lock(&mgr->lock); fprintf(stdout,"------------------------->删除链表重复元素<-----------------------------\n"); listNode *cur = mgr->head; listNode *head = NULL; int *flag = mgr->flag,i = 0; mgr->len = 0; while(cur != NULL && i >= 0) { listNode *pnext = cur->next; if(i == 0){ mgr->vmax = cur->v; mgr->head = head = cur; mgr->len++; }else { if(flag[cur->v] >= 1){ head->next = cur; head = cur; flag[cur->v] = -1; if(i != 0){ if(mgr->vmax <= cur->v) mgr->vmax = cur->v; if(mgr->vmin >= cur->v) mgr->vmin = cur->v; } mgr->len++; } } i++; cur = pnext; } pthread_mutex_unlock(&mgr->lock); return mgr->head; } listNode *listDRepeat(listMgr *mgr) { pthread_mutex_init(&mgr->lock,NULL); pthread_mutex_lock(&mgr->lock); fprintf(stdout,"*************************删除链表有重复元素*****************************\n"); int i = 0; listNode *p = mgr->head; listNode *head,*tail; head = tail = NULL; mgr->len = 0; int *flag = mgr->flag; while(p != NULL) { listNode *next = p->next; if(flag[p->v] == 1) { if(head == NULL) { mgr->head = head = tail = p; mgr->vmax = p->v; } else{ if(mgr->vmax <= p->v){ mgr->vmax = p->v; } if(mgr->vmin >= p->v){ mgr->vmin = p->v; } tail->next = p; tail = p; } tail->next = NULL; mgr->len++; } p = next; } pthread_mutex_unlock(&mgr->lock); return mgr->head; } listNode *listInit(listMgr *mgr,listNode *a,int n,int max) { if(n <= 0) { return NULL; } if(n > max) { n = max; } int i = 0; pthread_mutex_init(&mgr->lock,NULL); pthread_mutex_lock(&mgr->lock); listMgrInit(mgr,max); int *flag = mgr->flag; fprintf(stdout,"**************************原始链表*****************************\n"); for(i = 0;i < n;i++) { a[i].v = rand()%max; if(flag[a[i].v] == -1) { flag[a[i].v] = 1; }else{ flag[a[i].v]++; } if(i == 0){ mgr->vmax = a[i].v; mgr->vmin = a[i].v; }else{ if(mgr->vmax <= a[i].v){ mgr->vmax = a[i].v; } if(mgr->vmin >= a[i].v){ mgr->vmin = a[i].v; } } listNode *cur = &a[i]; if(i == n -1){ a[i].next = NULL; fprintf(stdout,"%d\n",cur->v); break; } a[i].next = &a[i+1]; fprintf(stdout,"%d ->",cur->v); } mgr->len = n; mgr->head = a; fprintf(stdout,"\nhead->v =%d,len=%d,max =%d,vmin=%d\n",mgr->head->v,mgr->len,mgr->vmax,mgr->vmin); fprintf(stdout,"\n"); pthread_mutex_unlock(&mgr->lock); return a; } void listPrt(listNode *p) { listNode *cur = p; while(cur != NULL) { if(cur->next == NULL) { fprintf(stdout,"%d\n\n",cur->v); break; } fprintf(stdout,"%d ->",cur->v); cur = cur->next; } } listNode *listOrder(listMgr *mgr) { pthread_mutex_init(&mgr->lock,NULL); pthread_mutex_lock(&mgr->lock); fprintf(stdout,"----------------->链表排序<------------------------------------\n"); listNode *cur = mgr->head; int max = mgr->vmax; int i = mgr->vmin; int *flag = mgr->flag; listNode *head,*tail; head = tail = NULL; for(;i <= max;i++) { if(flag[i] >0 && cur != NULL) { cur->v = i; listNode *n = cur->next; if(head == NULL) mgr->head = head = tail = cur; else { tail->next = cur; tail = cur; } tail->next = NULL; flag[i--]--; cur = n; } else continue; } pthread_mutex_unlock(&mgr->lock); return mgr->head; } int main(void) { listNode a[listSize]; listNode *tmp = NULL; listMgr mgr; listNode *ai = listInit(&mgr,&a[0],56,17); mgr.head = ai; tmp = listQuick(&mgr,rand()%10-1); listPrt(tmp); fprintf(stdout,"head->v =%d,len=%d,max =%d,vmin=%d\n\n",mgr.head->v,mgr.len,mgr.vmax,mgr.vmin); ai = listInit(&mgr,&a[0],56,17); tmp = listNRepeat(&mgr); listPrt(tmp); fprintf(stdout,"head->v =%d,len=%d,max =%d,vmin=%d\n\n",mgr.head->v,mgr.len,mgr.vmax,mgr.vmin); ai = listInit(&mgr,&a[0],56,17); tmp = listDRepeat(&mgr); listPrt(tmp); fprintf(stdout,"head->v =%d,len=%d,max =%d,vmin=%d\n\n",mgr.head->v,mgr.len,mgr.vmax,mgr.vmin); ai= listInit(&mgr,&a[0],56,17); tmp = listOrder(&mgr); listPrt(tmp); fprintf(stdout,"head->v =%d,len=%d,max =%d,vmin=%d\n\n",mgr.head->v,mgr.len,mgr.vmax,mgr.vmin); return 0; }
运行结果:
zhoulin@:~/code/c_src/algorithm/list_op:./list_op **************************原始链表***************************** 10 ->15 ->9 ->0 ->15 ->3 ->3 ->14 ->11 ->2 ->5 ->14 ->3 ->2 ->12 ->5 ->11 head->v =10,len=17,max =15,vmin=0 **************************v=5,大于v的节点在v节点右侧,否则在左侧***************************** 0 ->3 ->3 ->2 ->3 ->2 ->5 ->5 ->10 ->15 ->9 ->15 ->14 ->11 ->14 ->12 ->11 head->v =0,len=17,max =15,vmin=0 **************************原始链表***************************** 6 ->14 ->1 ->8 ->2 ->5 ->14 ->5 ->8 ->4 ->14 ->11 ->0 ->15 ->10 ->0 ->6 head->v =6,len=17,max =15,vmin=0 ------------------------->删除链表重复元素<----------------------------- 6 ->14 ->1 ->8 ->2 ->5 ->4 ->11 ->0 ->15 ->10 ->6 head->v =6,len=12,max =15,vmin=0 **************************原始链表***************************** 16 ->3 ->10 ->4 ->14 ->3 ->9 ->2 ->6 ->2 ->6 ->3 ->13 ->10 ->9 ->2 ->11 head->v =16,len=17,max =16,vmin=2 *************************删除链表有重复元素***************************** 16 ->4 ->14 ->13 ->11 head->v =16,len=5,max =16,vmin=2 **************************原始链表***************************** 9 ->4 ->0 ->6 ->0 ->16 ->10 ->5 ->10 ->10 ->4 ->3 ->2 ->1 ->10 ->5 ->2 head->v =9,len=17,max =16,vmin=0 ----------------->链表排序<------------------------------------ 0 ->0 ->1 ->2 ->2 ->3 ->4 ->4 ->5 ->5 ->6 ->9 ->10 ->10 ->10 ->10 ->16 head->v =0,len=17,max =16,vmin=0