C Program for Multiplication using shift add method is : -

//importing library
#include<stdio.h>

int main(){
    int a, b, c;
    printf("Enter an integer: \n");
    scanf("%d", &a);
    printf("Enter an integer: \n");
    scanf("%d", &b);

    //multiply(a, b);

    c = 0; //product

    while(b != 0)
    {
        if(b & '\x01' == 1)
        {
            c = c + a;
        }
        a = a << 1;
        b = b >> 1;
    }
    printf("The product is %d", c);
    return 0;
}
//Enjoy Coding.....