【C/C++】链表操作

 功能菜单：

******************************************************************
**                      链表操作菜单                              **
**      1、创建链表并输入结点数据(包含num和goal，num==0结束)      **
**      2、输出各结点数据                                         **
**      3、查询第i个结点的值                                      **
**      4、在num为i的结点之后插入一个值为x的结点                  **
**      5、删除num为i的结点                                       **
**      6、链表逆序                                               **
**      0、输入0退出程序                                          **
******************************************************************
直接上代码

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

struct Student{
	int num;
	int goal;
	struct Student *next;
};

void manu(){
	printf("******************************************************************\n");
	printf("**\t\t\t链表操作菜单			  	  **\n");
	printf("**\t1、创建链表并输入结点数据(包含num和goal，num==0结束)	  **\n");
	printf("**\t2、输出各结点数据                                         **\n");
	printf("**\t3、查询第i个结点的值                                      **\n");
	printf("**\t4、在num为i的结点之后插入一个值为x的结点                  **\n");
	printf("**\t5、删除num为i的结点                                       **\n");
	printf("**\t6、链表逆序                                               **\n"); 
	printf("**\t0、输入0退出程序                                          **\n"); 
	printf("******************************************************************\n");
	
}

struct Student *create(void){
	int n=0,cacu;
	struct Student *head;
	struct Student *p1,*p2;
	p1=p2=(struct Student *)malloc(sizeof(struct Student));
	head=NULL;
	scanf("%d",&p1->goal);
	cacu=1; 
	while(cacu!=0&&(p1->goal!=0)){
		n++;
		if(n==1) head=p1;
		else p2->next=p1;
		p2=p1;
		p1=(struct Student *)malloc(sizeof(struct Student));
		scanf("%d",&p1->goal);
	}
	p2->next=NULL; 
	return(head);	
}

void print(struct Student *head){
	struct Student *ph;
	ph=head;
	if(head!=NULL){
		printf("该链表中各节点依次为："); 
		do{
			printf("\t%d\t",ph->goal);
			ph=ph->next;
		}while(ph!=NULL);
		printf("\n");
	}
//	while((ph->num!=0)&&(ph->next!=NULL)){
//		printf("%d\n",ph->goal);
//		ph=(ph->next);
//	}
}

int geshu(struct Student *head){
	int flag=0;
	struct Student *ph;
	ph=head;
	if(head!=NULL){
		do{
			flag++;
			ph=ph->next;
		}while(ph!=NULL);
	}
	return flag;
}

void select(struct Student *head,int i){
	int ji=0;
	struct Student *ph;
	ph=head;
	if(head!=NULL){
		while(ph!=NULL){
			ji++;
			if(ji==i){
				printf("%d",ph->goal);	
			}
			ph=ph->next;
		} 
	}
}

struct Student *insert(struct Student *head, struct Student *stud ,int ii){ 
	 struct Student *p0, *p1, *p2,*pp;
	 int j=0;
	 p1=head;
	 pp==p1; 
	 p0=stud;
	 if (head==NULL){ 
		 head=p0; 
		 p0->next=NULL; 
	 }
	 else{
	 	 if(j==ii){
	 	 	//printf("!!!!!!");
	 	 	head=p0;
			p0->next=p1;
//	 	 	while (p1->next!=NULL){ 
//				  p2=p1; 
//				  p1=p1->next; 
//		 	}
		 	//printf("@@\n");
	 	 }else{
		 	 while ((j<ii) && (p1->next!=NULL)){ 
				  p2=p1; 
				  p1=p1->next; 
				  j++;
			 }
			 if ( ii <= j){ 
			 	 if(head==p1) head=p0;
			 	 else p2->next=p0;
			 	 p0->next=p1;
			 }
			 else { 
				 p1->next=p0; 
				 p0->next=NULL; 
			 }
	 	 } 
		 
	 }
	return(head);
} 

void delet(struct Student *head,int i){
	struct Student *p1, *p2;
	int j;
	p1 = head;
	if(geshu(head)>1){
		if(i!=1){
			for ( j=1; j<i && p1->next!=NULL; ++j ){
			p2 =p1; 
			p1 = p1->next;
			} 
			if ( j==i && p1->next != NULL ){ 
				p2->next = p1->next;
				free(p1); 
				head=p2;
				printf("已删除\n");
			}
		}else{
			p2 =p1; 
			p1 = p1->next;
			p2->next = p1->next;
			free(p1);
			head=p2;
			printf("已删除\n");
		}
	} else if(geshu(head)==1){
		free(p1);
		printf("已删除,链表已空\n");
	}
}

struct Student *nixu(struct Student *head){
	struct Student *p,*q,*pr;
	p = head;
	q = NULL;
	head = NULL;
	while(p){
		pr = p->next;
		p->next = q;
		q = p;
		p = pr;
	}
	head = q;
	print(head);
	return head;
}

int main(int argc, char *argv[]) {
	while(1){
		manu();
		int j;
		struct Student *pt;
		scanf("%d",&j);
		if(j==1){
			pt=create();
			//print(pt);
			printf("\n");
		}else if(j==2){
			print(pt);
			printf("结点个数为%d\n",geshu(pt));
		}else if(j==3){
			int shu;
			printf("请输入查询的结点数：");
			scanf("%d",&shu);
			printf("该结点对应值为：");
			select(pt,shu);
			printf("\n");
		}else if(j==4){
			int cha;
			struct Student *pq;
			printf("请输入要在第几个结点后插入：");
			scanf("%d",&cha);
			printf("插入数据：");
			pq=(struct Student *)malloc(sizeof(struct Student));
			scanf("%d",&pq->goal);
			pt=insert(pt,pq,cha);
			printf("\n");
		}else if(j==5){
			int dele;
			printf("请输入要删除的结点数：");
			scanf("%d",&dele);
			delet(pt,dele);
			printf("\n");
		}else if(j==6){
			printf("逆序后链表各结点值为：\n");
			pt=nixu(pt);
		}else if(j==0){
			exit(0);
		}else{
			printf("输入有误！\n");
		}
	}
	return 0;
}