Root of the Problem

Given positive integers B and N, find an integer A such that A^N is as close as possible to B. (The result A is an approximation to the Nth root of B.) Note that A^N may be less than, equal to, or greater than B.

Input: The input consists of one or more pairs of values for B and N. Each pair appears on a single line, delimited by a single space. A line specifying the value zero for both B and N marks the end of the input. The value of B will be in the range 1 to 1,000,000 (inclusive), and the value of N will be in the range 1 to 9 (inclusive).

Output: For each pair B and N in the input, output A as defined above on a line by itself.

 #include <iostream>

 #include <cmath>

 #include <cstdlib>

 using namespace std;

 int main(){

     double b, n;

     while(cin >> b >> n){

         if(b ==  && n == )

             break;

         //pow:double pow(double, double)

         int a = (int)pow(b, / n);//直接取整，不是四舍五入 ,pow(a, n) < b

         if(b - pow(a, n) < pow(a + , n) - b)

             cout << a << endl;

         else

             cout << a +  << endl;

     }

     return ;

 }