c 双向链表

图片

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main(void){
struct film{
	char name[20];
	int id;
	struct film *pre;        //前向指针
	struct film *next;       //后向指针
};

	struct film *head=NULL;
	struct film *ls,*lspre,*work;
	int i=0;
	char input[20];
	while(i<3){
		puts("输入姓名：");
		fgets(input,20,stdin);

		work=(struct film*)malloc( sizeof(struct film));
		
		if(head==NULL){
			lspre=NULL;
			head=work;
		}
		else
			ls->next=work;

		work->next=NULL;
		work->pre=lspre;
		strcpy(work->name,input);
		work->id=i;
		i++;

		ls=work;
		lspre=work;
	}

//--------删除id=1 项--------------------------
	work=head;
	while(work!=NULL){
		if((work->id)==1){
	    	((work->pre)->next)=work->next;   //后向指针
		    (work->next)->pre=work->pre;      //前向指针
		} 
		work=work->next;
	}
	
    //--------利用pre反向显示--------------------------	
	work=lspre;
	while(work!=NULL){
			printf("%d %s\n",work->id,work->name);  
		work=work->pre;
	}
	
//-------链表遍历---------------------------------------------------
	work=head;
	while(work!=NULL){
//		printf("name:%s  id:%d\n",work->name,work->id );
		work=work->next;
	}
 //--------释放全部malloc------------------------------
	work=head;
	while(work!=NULL){	
        ls=work->next;       	
		free(work);
		work=ls;
	}
	return 0;
}