Power Of Numbers Java

PROGRAM TO WRITE POWER FUNCTION FOR LARGE NUMBERS

class MAIN {

// Maximum number of digits in

// output

static final int 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

static 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 > 0) {

    res[res_size] = carry % 10;

    carry = carry / 10;

    res_size++;

    }

    return res_size;

}

 

// This function finds

// power of a number x

static void power(int x, int n) {

     

    //printing value "1" for power = 0

    if(n == 0 ){

    System.out.print("1");

    return;

}

    int res[] = new int[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);

 

    System.out.print(x + "^" + n + " = ");

    for (int i = res_size - 1; i >= 0; i--)

    System.out.print(res[i]);

}

// Driver code

public static void main(String[] args) {

    int exponent = 100;

    int base = 2;

    power(base, exponent);

}

}




OUTPUT

2^100 = 1267650600228229401496703205376

CREDITS: https://www.geeksforgeeks.org/writing-power-function-for-large-numbers/