题解 | #[NOIP2010]数字统计#

#include <stdio.h>
int count = 0;
void A(int x)
{
    while (x)
    {
        if (x % 10 == 2)
        count++;
        x /= 10;
    }
    return;
}

int main() 
{
    int a,b;
    scanf("%d %d",&a,&b);
    for (int i = a;i <= b;i++)
    {
        A(i);
    }
    printf("%d",count);
    return 0;
}