1,字符向中间汇聚
#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<windows.h>
int main()
{
char ch[]=" ";
char a[]="My name is li xiao";
int i = 0,j = 17;
while(i<=j)
{
ch[i]=a[i];
ch[j]=a[j];
printf("%s\n",ch);
Sleep(500);
i++;
j--;
}
system("pause");
return 0;
}
2,
#include <stdio.h>
#include <string.h>
int main()
{
char key[]="123456";
char input[10];
int i=0;
for (i=0;i<3;i++)
{
printf("请输入密码:");
scanf("%s",input);
if(strcmp(key,input)==0)
{
break;
}
else
{
printf("密码输入错误\n");
}
}
if(i==3)
{
printf("三次密码输入错误\n");
}
else
{
printf("太厉害了,登录成功\n");
}
return 0;
}
3,输出一个整数的每一位:
#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<math.h>
int main()
{
int a=0;
int a1,a2,a3,a4,a5;
printf("请输入一个小于五位的数:",a);
scanf("%d",&a);
printf("你输入的数字是:%d\n",a);
a1=a%10;
a2=((a%100)-(a%10))/10;
a3=((a%1000)-(a%100))/100;
a4=((a%10000)-(a%1000))/1000;
a5=((a%100000)-(a%10000))/10000;
printf("个位数是:%d\n",a1);
printf("十位数是:%d\n",a2);
printf("百位数是:%d\n",a3);
printf("千位数是:%d\n",a4);
printf("万位数是:%d\n",a5);
return 0;
}
4,计算
#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
double sum=0;
int i;
for(i=1;i<=100;i++)
{
if(i%2==1)
{
sum=sum+1.0/i;
}
else if(i%2==0)
{
sum=sum-1.0/i;
}
}
printf("结果为:%1f",sum);
return 0;
}
5,出现多少次9:
#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<math.h>
int main()
{
int i;
int count=0;
char a[100]={0};
for(i=0;i<100;i++)
{
a[i]=i+1;
if ((a[i]%10==9)||((a[i]-(a[i]%10))/10==9))
{
count++;
printf("%d\n",a[i]);
}
}
printf("一共出现了%d次9",count);
return 0;
}