#include<stdio.h>  // 包含另一个文件

/* 这是一个简单的演示程序 */
int main()   // 函数名
{ // 函数体开始
	int num; // 声明
	num = 1; // 赋值表达式语句
	printf("Hello World\n"); // 调用函数
	return 0; // return 语句
} // 结束

#include<stdio.h>

int main()
{
	printf("Storage size for int : %d \n", sizeof(int));
	return 0;
}

unsigned int a;
int b = -1;
a = b;
printf("a=%u",a);

#include<stdio.h>

int main()
{
	int i = 2147483647;
	unsigned int j = 4294967295;
	printf("%d %d %d\n", i, i+1, i+2);
	printf("%u %u %u\n", j, j+1, j+2);

	return 0;
}

#include<stdio.h>
#define WORD "Hello World!"
#define OP 6+6
#define LINE 10

int main()
{
	char str[15] = WORD;
	int sum = OP;

	for(int i = 0; i < LINE; i++)
	{
		printf("%d\t%s\t%d\n", i, str, sum);
	}

	return 0;
}

#include<stdio.h>
#define MEAN(X,Y) ((X)+(Y))/2

int main()
{
	int mean = MEAN(10, 20);
	printf("%d", mean);

	return 0;
}

#include<stdio.h>
#define SQUARE(X) X*X

int main()
{
	int x = 5;
	printf("%d\n", SQUARE(x));
	printf("%d\n", SQUARE(x+2));
	printf("%d\n", 100/SQUARE(2));

	return 0;
}

#define MAX(X,Y) ((X) > (Y) ? (X) : (Y))
#define ABS(X) ((X) < 0 ? -(X) : (X))
#define ISSIGN(X) ((X) == '+' || (X) == '-' ? 1 : 0)

#include<stdio.h>

int main()
{
	int a = 5;
	printf("%d\n", ++a);
	printf("%d\n", a++);

	return 0;
}

#include<stdio.h>

int main()
{
	int  a = 5;
	printf("%d\n", sizeof a);
	printf("%d\n", sizeof int);	// 报错 
	printf("%d\n", sizeof(int));

	return 0;
}

#include<stdio.h>

int main()
{
	printf("Do not believe what is passed from mouth; \
Do not believe rumors ; Do not believe the \
infallibility of texts") ;

	return 0;
}

printf("%d,%d,%d", &a, &b, &c);

#include<stdio.h>

int main()
{
	char a[20];
	int sign, b, c;
	while(true)
	{
		sign = scanf("%s %d %d", a, &b, &c);
		printf("返回:%d\n", sign);
	}

	return 0;
}

while (~scanf("%d %d",&n,&m)) 等效于 while (scanf("%d %d",&n,&m) != EOF)

if(ch >= 'a' && ch <= 'z' || ch >= 'A' && ch <= 'Z')
{
	printf("is alphabet")
}

x = (y < 0) ? -y : y; 

// 等效于
if (y < 0)
	x = -y;
else
	x = y;

#include<stdio.h>

int main()
{
	int count = 0;
	char ch;
	while((ch = getchar()) != '\n')
	{
		switch(ch)
		{
			case 'a':
			case 'A':
				count++;
				break;
			case 'e':
			case 'E':
				count++;
				break;
			case 'i':
			case 'I':
				count++;
				break;
			case 'o':
			case 'O':
				count++;
				break;
			case 'u':
			case 'U':
				count++;
				break;
		}
	}
	printf("count: %d", count);

	return 0;
}

#include<stdio.h>

int main()
{
	char ch;
	while(scanf("%c", &ch) != EOF)
	{
		if(ch >= '0' &&ch <= '9')
			printf("%c", ch);
	}

	return 0;
}

#include<stdio.h>

int main()
{
	int num, status;
	int sum = 0;

	status = scanf("%d", &num);

	while(status = 1)
	{
		sum += num;
		if(sum >= 10)
			status = 0;
	}
	printf("%d", sum);

	return 0;
}

1 = status	// 语法错误
1 == status	// 返回真假

while(scanf("%d", &num) == 1)
	; 			// 跳过整数输入

	int i = 0;
	while(i > 5);
	{
		i++;
		printf("%d", i);
	} /* 输出：1*/


	int i;
	for(i = 0; i < 5; i++);
	{
		printf("%d", i);
	} /* 输出：5*/


	int i = 5;
	if(i > 999);
	{
		printf("%d", i);
	} /* 输出：5*/

#include<stdio.h>

int main()
{
	int i;
	for (i = 1; i <= 200; i+=2)
	{
		printf("%d", i);
		printf("%c", (i + 1) % 20 ? '\t': '\n' );
	}
	
	return 0;
}

#include<stdio.h>

int main()
{
	int i, k;
	for (i = 1, k = 1; i <= 200; i+=2, k++)
	{
		printf("%d", i);
		if(k % 10 == 0)
			printf("\n");
		else
			printf("\t");
	}

	return 0;
}

houseprice = 259,500;

for(; test ; ){}

/* 等效于 */
while (test){}

初始化;
while( 测试 )
{
	其他语句
	更新语句
}

/* 等效于 */
for( 初始化; 测试 ; 更新 )
	其他语句

#include<stdio.h>
#define PASSWORD 123456

int verify_password(int num)
{
	if(num == PASSWORD)
		return 0;
	else
		return 1;
}

int main()
{
	int password;
	do
	{
		printf("Please enter password:");
		scanf("%d", &password);
	}
	while(verify_password(password));
	printf("success!");

	return 0;
}

#include<stdio.h>

int max(int, int);	// 函数原型

int main()
{
	int a, b, num;
	scanf("%d %d", &a, &b);
	num = max(a, b);	// 函数调用
	printf("%d", num);

	return 0;
}

int max(int a, int b)	// 函数定义
{
	return a > b ? a : b;	// 返回int类型的值
}

int max(int a, int b)	// 函数定义
{
	return a > b ? a : b;	// 返回int类型的值
}

int main()
{
	int a, b, num;
	scanf("%d %d", &a, &b);
	num = max(a, b);	// 函数调用
	printf("%d", num);

	return 0;
}

#include<stdio.h>

int max(int, int);	// 函数原型
char max(char, char);

int main()
{
	int a, b;
	char ch1, ch2;

	scanf("%d %d", &a, &b);
	printf("max: %d\n\n", max(a, b));

	getchar(); // 读取换行
	scanf("%c %c", &ch1, &ch2);
	printf("char is %c and %c\n", ch1, ch2);
	printf("max: %c\n", max(ch1, ch2));

	return 0;
}

int max(int a, int b)	// 函数定义
{
	return a > b ? a : b;	// 返回int类型的值
}

char max(char a, char b)
{
	return a > b ? a : b;
}

#include<stdio.h>

void find_max(int a, int b, int &max)
{
	max = a > b ? a : b;
}

int main()
{
	int a, b, max;
	scanf("%d %d", &a, &b);
	find_max(a, b, max);
	printf("max: %d\n", max);

	return 0;
}

#include<stdio.h>

char *input()
{
	char str[20];
	scanf("%s", str);
	return &str[0];
}

int main()
{
	char *str = input();
	printf("%s", str);

	return 0;
}

int main()
{
    int i1,i2,i3,i4 ... i10;
    scanf("%d%d%d ... %d",&i1,&i2,&i3 ... &i10);
    i1 *= i1;
    i2 *= i2;

    .....

    printf("%d%d%d.....%d",i1,i2,i3....i10);
}

数据类型 数组名 [整形常量表达式], ...
type arrayName [ arraySize ];

int main()
{
    float candy[365] /*内含有365个float类型元素的数组 */
    char code[20];  /*内含有20个char类型元素的数组 */
    int book[50];   /*内含有50个int类型元素的数组 */
}

int main()
{
    int numbers[8] = {1,2,4,5,7,9,12,435};
}

double balance[] = {1000.0, 2.0, 3.4, 7.0, 50.0};

//下面是一个为数组中某个元素赋值的实例：

numbers[4] = 50.0;

//下面是为数组的所有元素进行赋值

int main()
{
    int num[5];
    for(int i = 0;i < 4;i ++)
        num[i] = i + 1;
}

int bao[20];

#include "stdio.h"
int main()
{
    int lihao[3] = {1,2,3};
    for(int i =0;i < 7;i ++)
        printf("%d\n",lihao[i]);
    return 0;
}
/*
1
2
3
3
11692832
0
4199400
*/

#define SIZE 4;
int main()
{
    int arr[SIZE];
    for(int i = 0;i < SIZE;i ++)

    ...

    return 0;
}

int main()
{
    int i = 0,j = 0;
    int a[10] = {3,1,4,1,5,9,2,6,5,4};
    for(i = 0;i < 9;i ++)
    {
        int temp = 0;
        for(j = 0;j < 9 - i;j ++)
        {
            if(a[j] > a[j + 1])
            {
                //将位置 j + 1 的数与位置j的数进行交换
                temp = a[j + 1];
                a[j + 1] = a[j];
                a[j] = temp;
            }
        }
    }
    for (i = 0;i < 10;i ++)
        printf("%d ",a[i]);
    return 0;  
}

/*
1 1 2 3 4 4 5 5 6 9
*/

#include "stdio.h"
int main()
{
    int i = 0,j = 0;
    int temp = 0;
    int a[10] = {3,1,4,1,5,9,2,6,5,4};
    for(i = 0;i < 9;i ++)
    {
        int pos = 0;
        for(j = 1;j < 10 - i;j ++)
            if(a[pos] < a[j])
                pos = j;
        if(pos != 9 - i)
        {
            temp = a[9 - i];
            a[9 - i] = a[pos];
            a[pos] = temp;
        }
    }
    for (i = 0;i < 10;i ++)
        printf("%d ",a[i]);
    return 0;  
}
/*
1 1 2 3 4 4 5 5 6 9
*/

type name[size1][size2]...[sizeN];

int threedim[5][10][4];

数据类型 数组名[整型常量][整形常量] = { {数据1,...} , {数据2,...}, {数据3,...}, ...};

int a[3][4] = {
    {0, 1, 2, 3}, /*  初始化索引号为 0 的行 */
    {4, 5, 6, 7},  /*  初始化索引号为 1 的行 */
    {8, 9, 10, 11}  /*  初始化索引号为 2 的行 */
};

int a[][4] = { {0, 1, 2, 3}, {4, 5, 6, 7}, {8, 9, 10, 11} };

int a[3][4] = { {0, 1, 2, 3}, {4, 5, 6, 7}, {8, 9, 10, 11} };

int val = a[2][3];

/* 一个带有 3 行 4 列的数组 */
int a[3][4];

int i, j;
for(i = 0;i < 3;i ++ )
{
    for(j = 0;j < 4;j ++)
    {
        scanf("%d",&a[i][j]);
    }
}

//输出具体数值
for ( i = 0; i < 3; i++ )
{
    for ( j = 0; j < 4; j++ )
        printf("%d ",a[i][j]);
    printf("\n");
}
/*
1 2 3 4
3 4 5 6
5 6 7 8
*/
    for ( j = 0; j < 4; j++ )
        printf("a[%d][%d] = %d\n", i,j, a[i][j]);
/*
a[0][0] = 1
a[0][1] = 2
a[0][2] = 3
a[0][3] = 4

a[1][0] = 3
a[1][1] = 4
a[1][2] = 5
a[1][3] = 6

a[2][0] = 5
a[2][1] = 6
a[2][2] = 7
a[2][3] = 8
    */
}

int num[2][4][2];

int mian()
{
    int address[3][6][4];
    for(int i = 0;i < 3;i ++)
    {
        printf("第%d栋楼\n\n"，i);
        for(int j = 0;j < 6;j ++)
        {
            printf("第%d层楼"，6 - j);
            for(int k = 0;k < 4;k ++)
            {
                address[i][j][k] = k + 1;
                printf("%d",address[i][j][k]);
            }
        }
    }
}

int  var1;
char var2[10];
//打印出地址
printf("var1 变量的地址： %p\n", &var1  );
printf("var2 变量的地址： %p\n", &var2  );
/*
var1 变量的地址： 0x7fff5cc109d4
var2 变量的地址： 0x7fff5cc109de
*/

scanf("%d",&i);//传入一个地址
//scanf的函数原型
int scanf(const char * restrict format,...);

数据类型* 变量名  或  数据类型 *变量名 //只是*的位置不同而已

int *pointer;
char *name;

 int a = 10,*p;  
 p = &a
 int a = 10;
 int *p = &a;

int  *ptr = NULL;
printf("ptr 的地址是 %p\n", ptr  );
return 0;
/*
结果：
ptr 的地址是 0x0
*/

printf("%p",p)   //结果是一个地址(p指向的变量a的地址)。
printf("%d",*p)  //结果是10，变量a的值。
printf("%d",&p)  //结果是一个地址(指针p的地址，因为指针也是一个变量自己也有地址的)

int a = 5;
int *i = &a;
printf("%p\n",i);
i ++;
printf("%p\n",i);
i -= 2;
printf("%p\n",i);
return 0;
/*
000000000062FE44
000000000062FE48
000000000062FE40
*/

int *p_i = NULL;   //定义指针变量
int num[5] = {1，2，3，4，5};
for(int i = 0;i < 5;i ++)
{
    p_i = &num[i];  //先让指针指向想要输出的数据
    printf("%d ",*p_i); //通过指针输出数组数据
}

int num[5] = {1,2,3,4,5};
int *p_i;

p_i = &num[0];

p_i = num;

int num[5] = {2,4,6,8,10};
for(int i = 0;i < 5;i ++)
{
    //通过数组下标遍历数组
    printf("%d",num[i]);
    //通过指针变量遍历数组
    printf("%d",*(num + i));
}

int num[3][2] = {{1,2},{3,4},{5,6}};
int *p_i = &num[0][0];

double arr[4][3] = {
    {78.4,72.1,41.2},
    {56.4,12.4,45.1},
    {12.5,14.6,20.4},
    {23.5,34.6,67.8}
}
double *p_d = &arr[0][0]; //指针变量的类型必须要跟数组类型一致
printf("二维数组中arr[3][2]位置上的数据为：%6.11f\n",*(p_d + 3 * 3 + 2));

int *ptr_array[10]

int main()
{
  int a = 16, b = 932, c = 100;
  //定义一个指针数组
  int *arr[3] = {&a, &b, &c};
  printf("%d %d %d\n", *arr[0], *arr[1], *arr[2]);
  return 0;
}
/*
16 932 100
*/

datatype (*ptr)[length];

       a[][0]  a[][1]  a[][2]
a[0]     0        2        3
a[1]     1        5        6
a[2]     2        3        4
a[3]     7        8        9

int (*p)[3] = a;  

#include "stdio.h"

void add_five(int *);
int main()
{
    int i = 10;
    add_five(&i);
}

void add_five(int *a)
{
    *a = *a + 5;
}

#include "stdio.h"
int main()
{
    char name[20] = "baoqianyue";
    int height = 175;
    int weight = 70;
    char sex = 'm';
    short age = 19;
    long  wealth  = 300000;
    printf("鲍骞月的个人信息：\n");
    printf("姓名：%s,身高：%d,性别：%c,年龄：%d,财产：%d\n",name,height,sex,age,wealth);
    return 0;
}

struct 结构类型名
{
    数据类型1 成员变量1;
    数据类型2 成员变量2;
    数据类型3 成员变量3;
    ....
}; //<- 需要注意的地方

struct Stu{
    int height;//身高
    int weight;//体重
    char sex;//性别
    int age; //年龄
    long wealth;
};

struct student stu1,stu2;

strcut 结构类型名 结构变量 = {数据1，数据2,...};

结构体变量名.成员名;

    Stu stu1;
    stu1.age = 19;
    stu1.height = 175;
    stu1.sex = 'm';
    stu1.wealth = 30000;
    stu1.weight = 70;
    printf("身高：%d,性别：%c,年龄：%d,财产：%d\n",stu1.height,stu1.sex,stu1.age,stu1.wealth);

typedef StudentInfo Stu;
typedef int integer;

struct schedule{
    char name;
    char sex;
    int week1;
    int week2;
    int week3;
    int week4;
};

struct schedule{
    char name;
    char sex;
    int week[4];
};
//简化结构体的名字
typedef schedule S;

int main()
{
    S sd1 = {'A','m',1,2,4,6};
    S sd2 = {'A','m',3,5,6,7};
    S sd3 = {'A','m',2,3,5,7};
    printf("姓名：%c,性别：%c,工作日：%d %d %d %d",
        sd1.name,sd1.sex,sd1.week[0],sd1.week[1],sd1.week[2],sd1.week[3]);
    return 0;
}

int main()
{
    S st[3] = { {'A','m',1,2,4,6 } , {'A','m',3,5,6,7} , {'A','m',2,3,5,7} };
    for(int i = 0;i < 3;i ++)
    printf("姓名：%c,性别：%c,工作日：%d %d %d %d\n",
        st[i].name,st[i].sex,st[i].week[i],st[i].week[1],st[i].week[2],st[i].week[3]);
    return 0;
}

#include "stdio.h"
struct complex_num{
    int real;
    int image;
};
typedef complex_num comp;

comp assign(comp num)
{
    puts("输入复数的实部：");
    scanf("%d",&(num.real));
    puts("输入复数的实部：");
    scanf("%d",&(num.image));
    return num;
}

int main()
{
    comp com1;
    com1 = assign(com1);
    printf("%d + %di",com1.real,com1.image);
    return 0;
}

struct table{
    int i;
    char c;
    struct table *st;
};
int main()
{
    table st1 = {1,'a'};
    st1.st = &st1;
    //使用结构体变量输出自身的2个成员的值
    printf("%d %c\n",st1.i,st1.c);
    //使用结构体指针域所指向的结构体输出数值
    printf("%d %c\n",st1.st->i,st1.st->c);
    return 0;
}
/*
1 a
1 a
*/

int main()
{
    table st1 = {1,'a'};
    table st2 = {2,'b'};
    st1.st = &st2;

    //使用结构体变量输出st1自身的2个成员的值
    printf("%d %c\n",st1.i,st1.c);

    //使用结构体指针域所指向的结构体输出数值,即 st2 中的数值
    printf("%d %c\n",st1.st->i,st1.st->c);

    //使用结构体变量输出st2自身的2个成员的值
    printf("%d %c\n",st2.i,st2.c);

    return 0;
}
/*
1 a
2 b
2 b
*/

#include "stdio.h"
struct table{
    int i;
    char c;
    struct table *st;
};
int main()
{
    table tal[3] = {
        {1,'a'},
        {2,'b'},
        {3,'c'}
    };
    return 0;
}

struct table
{
    int i;
    char c;
    struct table *next;
}
strcut table st1 = {1,'a'};
struct table st2 = {2,'b'};
st1.next = &st2;

struct node
{
    short i;   数据域
    char c;   ///数据域
    struct node *next;  //指针域，用于指向下一个结点
}

struct node *p_head,*p_rail,*p_new ;

void malloc(unsigned int num_bytes);

struct node {
    short i;
    char c;
    struct node *next;
};

struct node node1 = {1,'A'};
struct node node2 = {2,'B'};
struct node node3 = {3,'C'};
node1.next = &node2;
node2.next = &node3;

struct node *p;
p = &node1;
for(int j = 0;j < 3;j ++)
{
    printf("node:%d %c",p->i,p->c);
    p = p->next;
}

struct node *p_new;
p_new = (struct node *)malloc(sizeof(struct node));
p_new->i = 4;
p_new->c = 'd';

node3.next = p_new;

struct node p_new = (struct node *)malloc(sizeof(struct node));  //创建新结点，并为其开辟空间
scanf("%d%c",&(p_new->i),&(p_new->c));  //录入结点数据
//插入节点
p_new->next = p_head-next;
p_head->next = p_new;

struct node p_new = (struct node *)malloc(sizeof(struct node));  //创建新结点，并为其开辟空间
p_new->i = 2;
p_new->c = 'B';

struct node *p_front = p_head->next;
p_new->next = p_front->next;
p_front->next = p_new;

while(1)
{
    if(p-next == NULL)
    {
        p_rail = p;
        break;
    }
    p = p->next;
}
p_rail->next = p_new;
p_tail = p_new;

void del_list(struct node *p_head,int pos)
{
    strct node *p_front,*p_del;
    p_front = p_head;
    for(int i = 0;i <= pos - 1;i ++)
    {
        p_front = p_front->next;
    }
    p_del = p_front->next;
    p_front->next = p_del->next;
    free(p_del);
}

char greeting[6] = {'H', 'e', 'l', 'l', 'o', '\0'};

char greeting[] = "Hello";

char arr[] = "Hello!";
int i = 0;
while(arr[i] != '\0')
{
    printf("%c",arr[i]);
    i ++;
}

char arr[] = "Hello!";
printf("%s\n",arr);

char arr[] = "Hello!";
int i = 0;
while(arr[i] != '\0')
{
    putchar(arr[i]);
    i ++;
}

int i = -1;
do
{
    i ++;
    scanf("%c",&arr[i]);
}while(arr[i] != '\n');
arr[i] = '\0';

scanf("%s",arr);

arr[i] = getchar();

char arr[10] = {0};
char *p = arr;
int i = -1;
do
{
    i ++;
    scanf("%d",p + i);
}while(*(p + i) != '\n');
*(p + i) = '\0';
i = 0;
while(*(p + i) != '\0')
{
    printf("%c",*(p + i));
    i ++;
}

cahr arr[20] = {0};
char *p = arr;
gets(p);
puts(p);

float f1 = 3.654;
float f2;
f2 = f1;

char *strcpy(char*des,char*src);
char *strncpy(char *des,char *src,int size);

char * strcat(const *char str1,const *char str2);
char *strncat(const *char str1,const *char str2,int size);

char *p1 = "super";
char *p2 = "market";
char *p3 = p1 + p2;  //错误的加法

char arr[30] = {0};
char *p3 = arr;
p3 = strcat(p3,p1);
p3 = strcat(p3,p2);
p3 = strncat(p3,p1,1);  //将p1所指向的字符的第一个字符加到p3所指字符串的末尾
// p3 = supermarkets

cahr arr[] = "Nes!";
cahr *p = arr;
*p = 'Y';

char *strset(char *s,char c);  //将字符串s中的字符全部设成字符 c
char *strnset(char *s,char c,int n); //将s指向的字符串的前n个字符都设成c

char p1[] = "Are you ok";
strset(p1,'a');
// p1 aaaaaaaaaa

strset(p2,'b',2);

//p1 bbaaaaaaaa

char arr[] = "What";
char arr2[] = "That";
if(arr1 == arr2)//错误的比较方式
{
    ...
}  

int strcmp(const char *str1,const char *str2);
int strncmp(const char *str1,const char *str2,int size);

char buf1[] = "aaa";
char buf2 = "bbb";
int ptr = strcmp(buf2,buf1);//ptr < 0

FILE *fopen( const char * filename, const char * mode );

"rb", "wb", "ab", "rb+", "r+b", "wb+", "w+b", "ab+", "a+b"

int fclose( FILE *fp );

#include "stdio.h"
#include "stdlib.h"
int main()
{
    //定义一个指向文件类型的指针
    FILE *fp;
    //打开一个已有的文件
    fp = fopen(text.txt,"r"); //错误的方式
    fp = fopen("D:\Desktop\text.txt","r");  //错误的方式
    if(fp == NULL )
    {
        printf("打开文件失败！\n");
        exit(0);
    }
    printf("打开文件成功！\n");
    fclose(fp);


    //如果想要在字符串中使用 '\' 必须要写成 '\\' 来转义
    fp = fopen("D:\\Desktop\\text.txt","r");
    //printf("D:\\Desktop\\text.txt\n");
    //printf("D:\Desktop\text.txt\n");

//使用访问模式 'w' 打开文件，会发现文件之前保存的内容被清零
    fp = fopen("D:\\Desktop\\text.txt","w");

    return 0;
}

int fputc(char c,FILE *stream);

char ch; //定义一个字符串
int i = 0;
while((ch = getchar()) != '\n')
{
    i = fputc(ch,fp);  // 以字符为单位，写入到text.txt文件
    if(i == -1)
    {
        puts("字符写入失败！");
        exit(0);
    }
}

int fprintf(FILE *stream,const char *format[, argument ] ...);

struct info
{
    short no;
    char name[10];
    char sex[6];
};

struct info info_st[3] ={
    {1,"baoqianyue","men"},
    {2,"lihao","men"},
    {3,"wanghao","men"}
};
for(int i = 0;i < 3;i ++)
{
    fprintf(fp,"No = %d\tname = %-8s\tsex = %-6s\n",info_st[i].no,
        info_st[i].name,info_st[i].sex);
}

int puts(const char *str,FILE *stream);

char c[100];
gets(c);
int value = fputs(c,fp);
if(value == -1)
{
    puts("字符串写入失败！\n");
    exit(0);
}

int fwrite(const void *buffer,int size,int count,FILE *stream);

struct info
{
    short no;
    char name[10];
    char sex[6];
};

struct info info_st[3] ={
    {1,"baoqianyue","men"},
    {2,"lihao","men"},
    {3,"wanghao","men"}
};

int count = fwrite(info_st,sizeof(struct info),3,fp);  //写入数据到文件

int fgetc(FILE *stream);

char ch = fgetc(fp);
while(ch != -1)
{
    putchar(ch);
    ch = fgetc(fp);
}

int fscanf(FILE *stream,const char *format[, argument ]...);

struct info
{
    short no;
    char name[10];
    char sex[6];
};

struct info info_st[3] ={
    {1,"baoqianyue","men"},
    {2,"lihao","men"},
    {3,"wanghao","men"}
};
for(int i = 0;i < 3;i ++)
{
    fscanf(fp,"No = %d\tname = %-8s\tsex = %-6s\n",&info_st[i].no,
       &info_st[i].name,&info_st[i].sex);
}

char *fgets(char *str,int n,FILE *stream);

char arr[15] = {0};
char *p = fgets(arr,15,fp);
while(p != NULL)
{
    printf("%s",arr);
    p = fgets(arr,15,fp);
}

int fr(eadconst void *buffer,int size,int count,FILE *stream);

int count = fread(info_st,sizeof(struct info),3,fp);  //从文件读取数据