1.计算s=22+42+62+……+1002
(1)for循环
#include"stdio.h"
int main()
{
int i;
long s;
s=0;
for(i=22;i<=1002;i+=20)
s=s+i;
printf("%d\n",s);
return 0;
}
(2)while循环
#include"stdio.h"
int main()
{
int i;
long s;
s=0;
i=22;
while(i<=1002)
{
s=s+i;
i+=20;
}
printf("%d\n",s);
return 0;
}
(3)do while 循环
#include"stdio.h"
int main()
{
int i;
long s;
s=0;
i=22;
do{s=s+i;i+=20;}
while(i<=1002);
printf("%d\n",s);
return 0;
}
2.水仙花数
#include <stdio.h>
int main()
{
int a, b, c, n,d;
d=0;
printf("result is:\n");
for( n=100; n<1000; n++ )
{
a = n / 100;
b = (n-a*100) / 10;
c = n % 10;
if(n == a*a*a + b*b*b + c*c*c)
{
printf("%d ", n);
d=d+1;
}
}
printf("\n");
printf("%d\n",d);
return 0;
}
3.三位数
#include "stdio.h"
int main() {
int i,j,k,t,n; n=0;
for(t=0,i=1;i<=5;i++)
for(j=1;j<=5;j++)
if(j!=i)
for(k=1;k<=5;k++)
if(k!=i && k!=j)
{
n=n+1;
printf(++t%12? "%4d":"%4d\n",i*100+j*10+k);
}
printf("The number of three digits is:%d\n",n);
return 0;
}