6.27-6.29 旧c语言

#include<stdio.h>
struct stu
{int num;float score;struct stu *next;
};
void main()
{struct stu a,b,c,*head;//静态链表a.num = 1;a.score = 10;b.num = 2;b.score = 20;c.num = 3;c.score = 30;head = &a;a.next = &b;b.next = &c;do{printf("%d,%5.1f\n",head->num,head->score);head = head->next;}while(head != NULL);
}

#include<stdio.h>
#include<stdlib.h>
#define LEN sizeof(struct stu)
int n;
struct stu
{int num;float score;struct stu *next;
};
struct stu *creat()//建立动态链表
{struct stu *p1,*p2,*head;p1 = p2 = (struct stu *)malloc(LEN);printf("input num:\n");scanf("%d",&p1->num);printf("input score:\n");scanf("%f",&p1->score);head = NULL,n = 0;while(p1->num != 0){n++;if(n == 1){head = p1;}else{p2->next = p1;}p2 = p1;//p1 = (struct stu *)malloc(LEN);printf("input num:\n");scanf("%d",&p1->num);printf("input score:\n");scanf("%f",&p1->score);}p2->next = NULL;return head;}
void print(struct stu *head)
{struct stu *p;printf("there are %d record stu\n",n);p = head;if(head != NULL){do{printf("num = %d,score = %f\n",p->num,p->score);p = p->next;}while(p);//直到p为空结点退出循环}
}
void main()
{struct stu *p;p = creat();print(p);
}

#include<stdio.h>//增删改查
#include<stdlib.h>
#define LEN sizeof(struct stu)
struct stu *del(struct stu *head,int n);
struct stu *creat();
void print(struct stu *head);
int n;
struct stu
{int num;float score;struct stu *next;
};
struct stu *del(struct stu *head,int m)
{struct stu *p1,*p2;p1 = head;if(head == NULL)//判断是否为空链表{printf("this is kong node\n");return NULL;}while(p1->num != m && p1->next != NULL)//删除的值不是当前结点，且当前结点不为尾节点{p2 = p1;p1 = p1->next;}if(p1->num == m)//找到节点{if(p1 == head)//如果当前节点为头结点{head = p1->next;}else//此时为普通结点{p2->next = p1->next;}printf("del NO：%d success!\n",m);n = n-1;}else{printf("%d no found!\n",n);}return head;
}
struct stu *creat()
{struct stu *p1,*p2,*head;p1 = p2 = (struct stu *)malloc(LEN);printf("input num:\n");scanf("%d",&p1->num);printf("input score:\n");scanf("%f",&p1->score);head = NULL,n = 0;while(p1->num != 0){n++;if(n == 1){head = p1;}else{p2->next = p1;}p2 = p1;p1 = (struct stu *)malloc(LEN);printf("input num:\n");scanf("%d",&p1->num);printf("input score:\n");scanf("%f",&p1->score);}p2->next = NULL;return head;}
void print(struct stu *head)
{struct stu *p;printf("there are %d record stu\n",n);p = head;if(head != NULL){do{printf("num = %d,score = %f\n",p->num,p->score);p = p->next;}while(p);}
}
void main()
{struct stu *stu,*p;int k;stu = creat();p = stu;print(p);printf("del num is:\n");scanf("%d",&k);print(del(p,k));
}

#include<stdio.h>
#include<stdlib.h>
#define LEN sizeof(struct stu)
struct stu *del(struct stu *head,int n);
struct stu *creat();
void print(struct stu *head);
struct stu *inser(struct stu *head,struct stu *ins);
struct stu *lookfor(struct stu *head,struct stu *look);
struct stu *wrilink(struct stu *head,struct stu *stu4);
struct stu
{int num;float score;struct stu *next;
};
int n;
struct stu *wrilink(struct stu *head,struct stu *stu4)
{struct stu *p;p = head;if(head == NULL){printf("无数据可修改!\n");}else{while(p != NULL){if(p->num == stu4->num){p->score = stu4->score;}p = p->next;}}return head;
}
struct stu *lookfor(struct stu *head,struct stu *look)
{struct stu *p;p = head;if(p == NULL){printf("没有数据!\n");}else{while(p != NULL){if(p->num == look->num){printf("找到第%d个数据,分数为%f\n",p->num,p->score);}p = p->next;}}return head;
}
struct stu *inser(struct stu *head,struct stu *ins)
{struct stu *p1,*p2,*p0;p0 = ins;p1 = head;if(head == NULL){head = p0;p0->next = NULL;}else{while((p0->num >p1->num) && (p1->next != NULL)){p2 = p1;p1 = p1->next;}if(p0->num <= p1->num){if(p1 == head){head = p0;}else{p2->next = p0;}p0->next = p1;}else{p1->next = p0;p0->next = NULL;}n = n+1;return head;}
}
struct stu *del(struct stu *head,int m)
{struct stu *p1,*p2;p1 = head;if(head == NULL){printf("this is kong node\n");return NULL;}while(p1->num != m && p1->next != NULL){p2 = p1;p1 = p1->next;}if(p1->num == m){if(p1 == head){head = p1->next;}else{p2->next = p1->next;}printf("del NO：%d success!\n",m);n = n-1;}else{printf("%d no found!\n",n);}return head;
}
struct stu *creat()
{struct stu *p1,*p2,*head;p1 = p2 = (struct stu *)malloc(LEN);printf("input num:\n");scanf("%d",&p1->num);printf("input score:\n");scanf("%f",&p1->score);head = NULL,n = 0;while(p1->num != 0){n++;if(n == 1){head = p1;}else{p2->next = p1;}p2 = p1;p1 = (struct stu *)malloc(LEN);printf("input num:\n");scanf("%d",&p1->num);printf("input score:\n");scanf("%f",&p1->score);}p2->next = NULL;return head;}
void print(struct stu *head)
{struct stu *p;printf("there are %d record stu\n",n);p = head;if(head != NULL){do{printf("num = %d,score = %f\n",p->num,p->score);p = p->next;}while(p != NULL);}
}
void main()
{struct stu *stu,*p,stu2,stu3,stu4;int k;stu = creat();p = stu;print(p);printf("del num is:\n");scanf("%d",&k);print(del(p,k));printf("insert into the num:");scanf("%d",&stu2.num);printf("insert into the score:");scanf("%f",&stu2.score);p = inser(stu,&stu2);print(p);printf("请输入查找的数据是:");scanf("%d",&stu3.num);lookfor(stu,&stu3);printf("请输入修改的学号:");scanf("%d",&stu4.num);printf("请输入修改的学号数据:");scanf("%f",&stu4.score);p = wrilink(stu,&stu4);print(p);
}

typedef 声明新的类型名来代替已有的类型名，有利于程序通用与移植

#include<stdio.h>
typedef struct
{int year;int month;int day;
}date;
void main()
{date da;da.year = 1995;da.month = 8;da.day = 9;printf("%d--%d--%d\n",da.year,da.month,da.day);
}

#include<stdio.h>
typedef int num[100];//声明um为整型数组类型
void main()
{num n = {0};printf("%d\n",sizeof(n));
}

#include<stdio.h>
typedef void (*p)();
void fun()
{printf("funny\n");
}
void main()
{p p1;p1 = fun;//函数指针指向函数的入口p1();
}