范围，出现的数字可以替换

#include<stdio.h>
#include<stdlib.h>
int main()
{
    int n,y,m;
    int sum = 0;//计数器
    for (n = 1; n <= 100; n++)
    {
        m = n;//把n赋值给m
        while (m > 0)
        {
            y = m % 10;
            m = m / 10;
            if (y == 9)
                sum++;
        }
    }
    printf("%d",sum);
    return 0;
}