// power.cpp: compute the power of an integer
#include <iostream>
#include <sstream>
using namespace std;

const int base=3;
unsigned long long power1(unsigned long);
unsigned long long power2(unsigned long);

int main(int argc, char* argv[]) {
    if (argc != 3) return 0;
    int algo = atoi(argv[1]);
    unsigned long long (*power)(unsigned long);
    switch (algo) {
        case 1: power = &power1; break;
        case 2: power = &power2; break;
        default: return 0;
    }
    stringstream ss(argv[2]);
    unsigned long n;
    ss >> n;
    cout << base << "^" << n << " = " << power(n) << endl;
    return 0;
}

/**
 * -----------------------------------------------------------------------
 *  a straightforward algorihtm for computing base^n
 * -----------------------------------------------------------------------
 */
unsigned long long power1(unsigned long n) {
    unsigned long i;
    unsigned long long ret=1;
    for (unsigned long i=0; i<n; i++)
        ret *= base;
    return ret;
}

/**
 * -----------------------------------------------------------------------
 *  a recursive algorithm
 * -----------------------------------------------------------------------
 */
unsigned long long power2(unsigned long n) {
    unsigned long long ret;
    if (n == 0) return 1;
    if (n % 2 == 0) {
        ret = power2(n/2);
        return ret * ret;
    } else {
        ret = power2((n-1)/2);
        return base * ret * ret;
    }
}