NOIP2010普及组--数字统计

 1 #include <stdio.h>
 2 int main(int argc, char *argv[])
 3 {
 4     int l,r,i;
 5     int num=0;
 6     int s;
 7     freopen("two.in","r",stdin);
 8     freopen("two","w",stdout);
 9     scanf("%d%d",&l,&r);
10     
11     for(i=l;i<=r;i++)
12     {
13         s=i;                        //s代表当前处理数 
14         do
15         {
16             if((s%10)==2)             //看个位是否为2 
17             {
18                 num++;
19             }
20             s=s/10;                    //将个位舍去 
21         }
22         while(s>0);
23     }
24     printf("%d",num);
25     fclose(stdin);
26     fclose(stdout);
27     return 0;
28 }