【C语言】结构体基础下运用数组，指针编写习题

编写一个结构体数组程序，要求输入一个5长度为5的结构体，并将它打印出来，利用他的成绩排序，找出他们中最大值和最小值，运用id查找出他的信息、运用成绩查找出他的信息，运用年龄查找出他的信息，运用名字查找出他的信息

先定义一个结构体。

 typedef struct stu
{
	int id;
	char name[20];
	int age;
	float score;
}STU;

#include<stdio.h>
#include<string.h>
//结构体数组传参 
 typedef struct stu
{
	int id;
	char name[20];
	int age;
	float score;
}STU;

void scanf_student(STU student[],int length);
void print_student(STU student[],int length);
void sort_student(STU student[],int length);
STU max_student(STU *pstudent,int length);
STU min_student(STU *pstudent,int length);
STU find_id(STU *pstudent,int length,int id);
STU find_score(STU *pstudent,int length,float score);
STU find_age(STU *pstudent,int length,int age);
STU find_name(STU *pstudent,int length,int name); 

int main()
{
	STU student[5];
	scanf_student(student,5);
	printf("打印一下信息");
	print_student(student,5);
	printf("根据成绩排序");
	sort_student(student,5);
	 printf("\n");
	print_student(student,5);
	printf("最大分为："); 
	STU ret = max_student(student,5);
	printf("%d,%s,%d,%.1f\n",ret.id,ret.name,ret.age,ret.score);
	printf("最小分为："); 
	STU ret1 = min_student(student,5);
	printf("%d,%s,%d,%.1f\n",ret1.id,ret1.name,ret1.age,ret1.score);
	printf("根据id查找信息：");
	STU ret2 = find_id(student,5,1003);
	printf("%d,%s,%d,%.1f\n",ret2.id,ret2.name,ret2.age,ret2.score);
	STU ret3 = find_score(student,5,99);
	printf("根据成绩查找信息：");
	printf("%d,%s,%d,%.1f\n",ret3.id,ret3.name,ret3.age,ret3.score);
	STU ret4 = find_age(student,5,28);
	printf("根据年龄查找信息：");
	printf("%d,%s,%d,%.1f\n",ret4.id,ret4.name,ret4.age,ret4.score);
	printf("根据name查找信息：");
	STU ret5 = find_name(student,5,"wangming");
	printf("%d,%s,%d,%.1f\n",ret5.id,ret5.name,ret5.age,ret5.score);
	return 0;
}
void scanf_student(STU student[],int length)
{
	int i;
	for(i=0;i<length;i++)
	{
		scanf("%d%s%d%f",&student[i].id,student[i].name,&student[i].age,&student[i].score);
	}
	
}
void print_student(STU student[],int length)
{
	int i;
	for(i=0;i<length;i++)
	{
		printf("%d,%s,%d,%.1f\n",student[i].id,student[i].name,student[i].age,student[i].score);
	}
	
}
void sort_student(STU student[],int length)
{
	int i,j;
	STU temp;
	for(i=0;i<length-1;i++)
	{
		for(j=0;j<length-1-i;j++)
		{
			if(student[j].score>student[j+1].score)
			{
				temp = student[j];
				student[j] = student[j+1];
				student[j+1] = temp;
			}
		}
	}	
} 
STU max_student(STU *pstudent,int length)
{
	int i;
	STU temp;
	float max_score = pstudent[0].score;
	for(i=0;i<length;i++)
	{
		if(max_score<pstudent[0].score)
		{
			max_score = pstudent[0].score;
			temp = pstudent[i];
		}
	}
	return temp;
}
STU min_student(STU *pstudent,int length)
{
	int i;
	STU temp;
	float min_score = pstudent[0].score;
	for(i=0;i<length;i++)
	{
		if(min_score>pstudent[0].score)
		{
			min_score = pstudent[0].score;
			temp = pstudent[i];
		}
	}
	return temp;
}
STU find_id(STU *pstudent,int length,int id)
{
	int i;
	int flag; 
	STU temp = {0,NULL,0,0};
	for(i=0;i<length;i++)
	{
		if(id == pstudent[i].id)
		{
			return pstudent[i];
		}
		else
		{
			
			flag = 1;
		}
	}
	if(flag == 1)
	{
		printf("找不到该学号");
	}
}

STU find_score(STU *pstudent,int length,float score)
{
	int i;
	STU temp = {0,NULL,0,0};
	for(i=0;i<length;i++)
	{
		if(score == pstudent[i].score)
		{
			return pstudent[i];
		}
		else
		{
			printf("找不到该成绩");
			return temp;
		}
	}
}
STU find_age(STU *pstudent,int length,int age)
{
	int i;
	int flag;
	STU temp = {0,NULL,0,0};
	for(i=0;i<length;i++)
	{
		if(age == pstudent[i].age)
		{
			return pstudent[i];
		}
		else
		{
			flag = 1;
		}
	}
	if(flag == 1)
	{
		printf("找不到该年龄");
	}
}
STU find_name(STU *pstudent,int length,int name)
{
	int i;
	int flag;
	STU temp = {0,NULL,0,0};
	for(i=0;i<length;i++)
	{
		if(strcmp(pstudent[i].name,name) == 0 )
		{
			return pstudent[i];
			flag = 1;
		}
	}
	if(flag == 1)
	{
		printf("找不到该名字");
	}
}

/*1001 zhangsan 22 99
1002 lisi 24 88
1003 wangwu 25 79
1004 hanmei 28 96
1005 wangming 30 77*/

typedef与#define的区别

不同点在于：typedef仅限于数据类型，而不能是表达式或具体的值

#define发生在预处理，typedef发生在编译阶段

#define常量起名（简单的文字代替），typedef是给类型起别名（满足连续定义）

typedef的操作方法：简单的说，就是按定义变量的方式，把变量名换上新类型名，并且在最前面加“typedef”，就声明了新类型名代表原来的类型

typedef struct home
{
	int id;
	char name[20];
	char addr[20];
 }HOME;
 typedef struct per
 {
 	char name[20];
 	int age;
 	HOME *home;
 }PER;

创建了一个常量结构体跟指针结构体。