UVA 113
Background
Current work in cryptography involves (among other things) large prime numbers and computing powers of numbers modulo functions of these primes. Work in this area has resulted in the practical use of results from number theory and other branches of mathematics once considered to be of only theoretical interest.
This problem involves the efficient computation of integer roots of numbers.
The Problem
Given an integer and an integer
you are to write a program that determines
, the positive
root of p. In this problem, given such integers n and p, p will always be of the form
for an integer k (this integer is what your program must find).
The Input
The input consists of a sequence of integer pairs n and p with each integer on a line by itself. For all such pairs ,
and there exists an integer k,
such that
.
The Output
For each integer pair n and p the value should be printed, i.e., the number k such that
.
Sample Input
2 16 3 27 7 4357186184021382204544
Sample Output
4 3 1234
水题一个,最主要的问题就是数据量的控制,这里用的是double,其实long double应该也可以,还没有尝试,总之看代码吧:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include<stdio.h> #include<math.h> int main() { double n, p; while(scanf("%lf%lf", &n, &p) != EOF) { printf("%.0lf\n", pow(p, 1/n)); } return 0; }