Codeforces Eyad and Math Gym

Eyad was given a simple math problem, but since he is very bad at math he asked you to help him.

Given 4 numbers, a, b, c, and d. Your task is to find whether ab is less than cd or not.

It is guaranteed that the two numbers above are never equal for the given input.

Input
The first line contains an integer T (1 ≤ T ≤ 105), where T is the number of test cases.

Then T lines follow, each line contains four integers a, b, c, and d (1 ≤ a, b, c, d ≤ 109).

Output
For each test case, print a single line containing “<” (without quotes), if ab is less than cd. Otherwise, print “>” (without quotes).

Example
Input
2
9 2 5 3
3 4 4 3
Output
<
>

题目大意：
比较 a^b 与 c^d 的大小

思路： 取对数

代码：

#include<cstdio>#include<cstring>#include<iostream>#include<cmath>#include<algorithm>using namespace std;int main(){    int t;    scanf("%d",&t);    while(t--) {        double a,b,c,d;        scanf("%lf%lf%lf%lf",&a,&b,&c,&d);        double n1=b*log(a);        double n2=d*log(c);        if(n1>=n2)            printf(">\n");        else            printf("<\n");    }    return 0;}