C program to multiply two numbers without using multiplication operator

How to multiply two numbers without using Arithmetic(multiplication) operator?

Consider x and y are two integers whose values are 10 and 3 correspondingly.  Adding x for y times gives the product of x and y.

Example: x = 10, y = 3

Adding x for y times => 10 + 10 + 10 = 30 is the product of 10 and 3.

Please check the below link to know about how to add two numbers without using addition operator.

• How to add two numbers without using addition operator?

Write a C program to multiply two numbers without using arithmetic operator.

  #include <stdio.h>

  /* addition of two numbers without using addition operator */
  int addition(int a, int b) {
        int carry;
        while (b != 0) {
                /* calculating the carry and do a left shift*/
                carry = (a & b) << 1;
                /* calculating the sum */
                a = a ^ b;
                b = carry;
        }
        return a;
  }

  int main () {
        int num1, num2, res = 0, i;
        /* get the input from the user */
        printf ("Enter your first input:");
        scanf("%d", &num1);
        printf("Enter your second input:");
        scanf("%d", &num2);

        /*
         * Adding num1 for num2 times gives the product
         * value.  Product of two numbers without using
         * arithmetic operator.
         */
        for (i = 0; i < num2; i++) {
                res = addition(res, num1);
        }

        printf("product of %d and %d is %d\n", num1, num2, res);
        return 0;
  }

  Output:

  jp@jp-VirtualBox:~/$ ./a.out
  Enter your first input:100
  Enter your second input:35
  product of 100 and 35 is 3500