C语言实现顺序链表的创建和删除插入元素

约定不等于承诺〃 2022-05-27 01:50 149阅读 0赞

#include<stdio.h>
    #include<malloc.h>
    #define LEN sizeof(struct student)
    /*
    	顺序链表的创建、删除、插入操作
    */
    struct student{
    	int num;
    	float score;
    	struct	student *next;
    };
    int n;
    
    struct student *creat(){//创建链表;
    	struct student *head;//头结点
    	struct student *p1,*p2;
    	p1=p2=(struct student *)malloc(LEN);//分配内存
    
    	printf("\n请输入学号\n");
    	scanf("%d",&p1->num);
    	printf("\n请输入分数\n");
    	scanf("%f",&p1->score);
    
    	head=NULL;
    	n=0;
    
    	while(p1->num){
    		n++;
    		if(n==1){
    			head=p1;
    		}else{
    			p2->next=p1;
    		}
    		p2=p1;
    
    		p1=(struct student *)malloc(LEN);
    		printf("\n请输入学号");
    		scanf("%d",&p1->num);//输入为0则条件为0停止循环
    		printf("\n请输入分数");
    		scanf("%f",&p1->score);
    	}
    	p2->next=NULL;
    	return head;
    }
    
    void print(struct student *head){//输出链表
    	struct student *p;//定义指针
    	p=head;//指针传递
    	if(head){
    		do{
    			printf("\n学号为%d的成绩是:%f\n",p->num,p->score);
    			p=p->next;
    		}
    		while(p);
    	}
    	printf("\n共有%d个数据\n",n);
    }
    struct student *del(struct student *head,int num){//删除元素
    	struct student *p1,*p2;
    	if(head==NULL){
    			printf("\n空表\n");
    			goto END;
    	}else{
    		p1=head;
    		while(num!=p1->num&&p1->next!=NULL){//不是表尾节点
    			p2=p1;
    			p1=p1->next;
                }
    		if(p1->num==num){
    			if(p1==head){//判断是否为头结点
                       head=p1->next;//删除头结点
    			}
    			else{
                    p2->next=p1->next;
    			}
    			printf("\n删除%d成功",num);
    			n=n-1;
    		}
    		else{
    			printf("\n不存在的数据\n");
    		}
    
    	}
    END:
    	return head;
    }
    //*head是链表的头指针
    
    struct student *insert(struct student *head,struct student *stu_2){//第一个参数需要被插入的链表，第二个参数是插入的结构的地址
    	struct student *p0,*p1,*p2;//p0指向待插节点,p1p2遍历
    	p1=head;
    	p0=stu_2;
    	if(head==NULL){
    		head=p0;
    	}
    	else{
    		while((p0->num>p1->num)&&(p1!=NULL)){//开始条件为待插节点大于p0，结束条件为p1指向NULL
    			p2=p1;//p2跟随p1
    			p1=p1->next;//p1后移
    			if(p0->num<=p1->num){
    				if(p1==head){//p1若指向头结点
    					head=p0;//插到表头之前
    				}else{//插到表间
    				p2->next=p0;
    				}
    				p0->next=p1;
    			}else{//p0->num大于表中num
    				p1->next=p0;//插到表尾
    				p0->next=NULL;
    			}
    		}
    	}
    	n=n+1;
    	return head;
    }
    int main(){
    	struct student *stu,stu2,*p;
    	int a;
    
    	stu=creat(stu);
    	p=stu;
    
    	print(p);
        printf("\n");
        printf("请输入要删除学生的学号\n");
        scanf("%d",&a);
    	print(del(p,a));
    
    
    	printf("请输入要插入学生的学号\n");
    	scanf("%d",&stu2.num);
    	printf("请输入分数\n");
    	scanf("%f",&stu2.score);
    	print(insert(p,&stu2));
    
    	system("pause");
    return 0;
    }