NOIP2010普及组--数字统计

#include <stdio.h>
int main(int argc, char *argv[])
{
int l,r,i;
int num=0;
int s;
freopen("two.in","r",stdin);
freopen("two","w",stdout);
scanf("%d%d",&l,&r);

for(i=l;i<=r;i++)
{
s=i;                        //s代表当前处理数
do
{
if((s%10)==2)             //看个位是否为2
{
num++;
}
s=s/10;                    //将个位舍去
}
while(s>0);
}
printf("%d",num);
fclose(stdin);
fclose(stdout);
return 0;
}