源码地址 https://github.com/Wy2160640/C
001.第一个C程序
文件1.c
/* The first C programme */
#include <stdio.h> /* 包含标准输入输出头文件 */
main() /* 主函数 */
{
printf("Hello World!
"); /* 打印输出信息 */
}
编译运行
gcc 1.c ./a.out Hello World!
002.运行多个源文件
文件print.c
#include "print.h"
void printHello()
{
printf("hello word!
");
}
文件helloword.c
#include "print.h"
int main(void){
printHello();
return 0;
}
文件print.h
#include "stdio.h" void printHello(void);
编译运行
gcc print.c helloword.c ./a.out
003.求整数之积
文件3.c
/* Input two numbers, output the product */
#include <stdio.h>
main()
{
int x,y,m; /* 定义整型变量x，y，m */
printf("Please input x and y
"); /* 输出提示信息 */
scanf("%d%d",&x,&y); /* 读入两个乘数，赋给x，y变量 */
m=x*y; /* 计算两个乘数的积，赋给变量m */
printf("%d * %d = %d
",x,y,m); /* 输出结果 */
}
编译运行
gcc 3.c ./a.out
004.比较实数大小
/* 输入两个浮点数，输出它们中的大数 */
#include <stdio.h>
main()
{
float x,y,c; /* 变量定义 */
printf("Please input x and y:
"); /* 提示用户输入数据 */
scanf("%f%f",&x,&y);
c=x>y?x:y; /* 计算c=max(x,y) */
printf("MAX of (%f,%f) is %f",x,y,c); /* 输出c */
}
编译运行
gcc 4.c ./a.out
005.字符的输出
/* */
#include <stdio.h>
main()
{
char ch,nch; /* */
int count; /* */
int k; /* */
printf("Please input a string with a # in the end.
");
scanf("%c",&ch); /* */
while(ch != '#') /* */
{
if(ch >= '0' && ch <= '9')
{
/* */
count = ch-'0'+1; /* */
scanf("%c",&nch); /* */
for(k=0;k<count;k++) /* */
printf("%c",nch);
}
else
printf("%c",ch); /* */
printf(" "); /* */
scanf("%c",&ch); /* */
}
printf("#
"); /* */
}
编译运行
gcc 5.c ./a.out
006.显示变量所占字节数
/* 输出不同类型所占的字节数*/
#include <stdio.h>
void main()
{
/* sizeof()是保留字，它的作用是求某类型或某变量类型的字节数, */
/* 括号中可以是类型保留字或变量。*/
/*int型在不同的机器，不同的编译器中的字节数不一样,*/
/*一般来说在TC2.0编译器中字节数为2,在VC编译器中字节数为4 */
printf("The bytes of the variables are:
");
printf("int:%d bytes
",sizeof(int));
/* char型的字节数为1 */
printf("char:%d byte
",sizeof(char));
/* short型的字节数为2 */
printf("short:%d bytes
",sizeof(short));
/* long型的字节数为4 */
printf("long:%d bytes
",sizeof(long));
/* float型的字节数为4 */
printf("float:%d bytes
",sizeof(float));
/* double型的字节数为8 */
printf("double:%d bytes
",sizeof(double));
/* long double型的字节数为8或10或12 */
printf("long double:%d bytes
",sizeof(long double));
getchar();
}
编译运行
gcc 6.c ./a.out
007.自增自减运算
/* */
#include <stdio.h>
main()
{
int a=5,b,c,i=10;
b=a++;
c=++b;
printf("a = %d, b = %d, c = %d
",a,b,c);
printf("i,i++,i++ = %d,%d,%d
",i,i++,i++);
printf("%d
",++i);
printf("%d
",--i);
printf("%d
",i++);
printf("%d
",i--);
printf("%d
",-i++);
printf("%d
",-i--);
getchar();
}
编译运行
gcc 7.c ./a.out
008.数列求和
#include <stdio.h>
main()
{
int i,j,n;
long sum=0,temp=0;
printf("Please input a number to n:
");
scanf("%d",&n);
if(n<1)
{
printf("The n must no less than 1!
");
return;
}
for(i=1;i<=n;i++)
{
temp=0;
for(j=1;j<=i;j++)
temp+=j;
sum+=temp;
}
printf("The sum of the sequence(%d) is %d
",n,sum);
getchar();
getchar();
}
编译运行
gcc 8.c ./a.out
009.乘法口诀表
#include <stdio.h>
#include <conio.h>
void main(void)
{
int i,j,x,y;
clrscr();
printf("
* * * ³Ë·¨¿Ú¾÷±í * * *
");
x=9;
y=5;
for(i=1;i<=9;i++)
{
gotoxy(x,y);
printf("%2d ",i);
x+=3;
}
x=7;
y=6;
for(i=1;i<=9;i++)
{
gotoxy(x,y);
printf("%2d ",i);
y++;
}
x=9;
y= 6;
for(i=1;i<=9;i++)
{
for(j=1;j<=9;j++)
{
gotoxy(x,y);
printf("%2d ",i*j);
y++;
}
y-=9;
x+=3;
}
printf("
");
}
编译运行
gcc 9.c ./a.out
010.猜数字游戏
#include <stdio.h>
#include <conio.h>
void main()
{
int Password=0,Number=0,price=58,i=0;
clrscr();
printf("
====This is a Number Guess Game!====
");
while( Password != 1234 )
{
if( i >= 3 )
return;
i++;
puts("Please input Password: ");
scanf("%d",&Password);
}
i=0;
while( Number!=price )
{
do{
puts("Please input a number between 1 and 100: ");
scanf("%d",&Number);
printf("Your input number is %d
",Number);
}while( !(Number>=1 && Number<=100) );
if( Number >= 90 )
{
printf("Too Bigger! Press any key to try again!
");
}
else if( Number >= 70 && Number < 90 )
{
printf("Bigger!
");
}
else if( Number >= 1 && Number <= 30 )
{
printf("Too Small! Press any key to try again!
");
}
else if( Number > 30 && Number <= 50 )
{
printf("Small! Press any key to try again!
");
}
else
{
if( Number == price )
{
printf("OK! You are right! Bye Bye!
");
}
else if( Number < price )
{
printf("Sorry,Only a little smaller! Press any key to try again!
");
}
else if( Number > price )
printf(" Sorry, Only a little bigger! Press any key to try again!
");
}
getch();
}
}
编译运行
gcc 10.c ./a.out