个位9的数目+十位9的数目

#include<stdio.h>
int main()
{int num = 0;int count = 0;for (num = 1; num <= 100; num++){if (num % 10 == 9) //个位9的个数count++;if (num / 10 == 9)//十位9的个数count++;}printf("%d", count);return 0;
}