#### Power for Huge Numbers

```/**
* @file
* @brief Compute powers of large numbers
*/
#include <iostream>

/** Maximum number of digits in output
*  \f\$x^n\f\$ where \f\$1 <= x,\; n <= 10000\f\$ and overflow may happen
*/
#define MAX 100000

/** This function multiplies x
* with the number represented by res[].
* res_size is size of res[] or
* number of digits in the number
* represented by res[]. This function
* uses simple school mathematics
* for multiplication.
* This function may value of res_size
* and returns the new value of res_size
* @param x multiplicand
* @param res large number representation using array
* @param res_size number of digits in `res`
*/
int multiply(int x, int res[], int res_size) {
// Initialize carry
int carry = 0;

// One by one multiply n with
// individual digits of res[]
for (int i = 0; i < res_size; i++) {
int prod = res[i] * x + carry;

// Store last digit of
// 'prod' in res[]
res[i] = prod % 10;

// Put rest in carry
carry = prod / 10;
}

// Put carry in res and
// increase result size
while (carry) {
res[res_size] = carry % 10;
carry = carry / 10;
res_size++;
}
return res_size;
}

/** This function finds power of a number x and print \f\$x^n\f\$
* @param x base
* @param n exponent
*/
void power(int x, int n) {
// printing value "1" for power = 0
if (n == 0) {
std::cout << "1";
return;
}

int res[MAX];
int res_size = 0;
int temp = x;

// Initialize result
while (temp != 0) {
res[res_size++] = temp % 10;
temp = temp / 10;
}

// Multiply x n times
// (x^n = x*x*x....n times)
for (int i = 2; i <= n; i++) res_size = multiply(x, res, res_size);

std::cout << x << "^" << n << " = ";
for (int i = res_size - 1; i >= 0; i--) std::cout << res[i];
}

/** Main function */
int main() {
int exponent, base;
std::cout << "Enter base ";
std::cin >> base;
std::cout << "Enter exponent ";
std::cin >> exponent;
power(base, exponent);
return 0;
}
```