uva156

http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=49

113 - Power of Cryptography

Time limit: 3.000 seconds

Power of Cryptography

Background

Current work in cryptography involves (among other things) largeprime numbers and computing powers of numbers modulo functions ofthese primes. Work in this area has resulted in the practical useof results from number theory and other branches of mathematicsonce considered to be of only theoretical interest.

This problem involves the efficient computation of integer rootsof numbers.

TheProblem

Given an integer and an integer you are to write a program that determines , the positive root of p. In this problem, given suchintegers n and p, p will always be of the form for an integer k (this integer is what yourprogram must find).

TheInput

The input consists of a sequence of integer pairs n andp with each integer on a line by itself. For all such pairs , and there exists an integer k, such that .

TheOutput

For each integer pair n and p the value should be printed, i.e., the number k suchthat .

SampleInput

21632774357186184021382204544

SampleOutput

431234

这题其实是考察人的逆向思维。。。有点trick

#include<stdio.h>
#include<math.h>
int main()
{
 int k,i;
 double p,n;
 while(scanf("%lf %lf",&n,&p)!=EOF)
 {
  printf("%.lf\n",pow(p,1/n));//强制转化成int的话会有误差，可以用floor试试
 }
 return 0;
}