UVa - 113 Power of Cryptography

#include<stdio.h>

#include<float.h>

#include<math.h>

#include<assert.h>

#define EPSILON 0.01

double guess;

double n,p;

double nth_root_rec_bf_bs(double low,double high){

    if(abs(low-high) < EPSILON) return guess;

    guess=(low+high)/2;

    if(abs((pow(guess, n)) - p) <= EPSILON) return guess;

    if(pow(guess, n) > p) return nth_root_rec_bf_bs(low,guess);

    return nth_root_rec_bf_bs(guess,high);

}

inline double nthRoot(double x, double n){

    if(x==1) return 1;

    if(n==1) return x;

    if(x >= 0 and x <= 1) return nth_root_rec_bf_bs(x,1);

    if(x>1) return nth_root_rec_bf_bs(1,x);

assert(1==0);

}

int main(){

//        freopen("input.txt","r",stdin);

//        freopen("output.txt","w",stdout);   

    while (scanf("%lf%lf", &n, &p) == 2){

        printf("%.0lf\n", nthRoot(p,n));

    }

}