百练 2739 计算对数

题目链接：http://bailian.openjudge.cn/practice/2739

# include<stdio.h># include<math.h>int main(){int n;double a,b;scanf("%d",&n);while(n--){scanf("%lf%lf",&a,&b);printf("%d\n",int(log10(b)/log10(a)));}return 0;}