Project Euler：99 Largest exponential C++

Comparing two numbers written in index form like 2¹¹ and 3⁷ is not difficult, as any calculator would confirm that 2¹¹ = 2048 < 3⁷ = 2187.

However, confirming that 632382⁵¹⁸⁰⁶¹ > 519432⁵²⁵⁸⁰⁶ would be much more difficult, as both numbers contain over three million digits.

Using base_exp.txt (right click and 'Save Link/Target As...'), a 22K text file containing one thousand lines with a base/exponent pair on each line, determine which line number has the greatest numerical value.

NOTE: The first two lines in the file represent the numbers in the example given above.

用对数做，转化成 n=y*ln x，n为10的指数。也就是比较以10 为底，对数值的大小。

C++中，ln写作log。

实现部分如下：

int n=log(x)*y;
if(max<n){
    max=n;
    ans=num;
}

// ans= 709；