ancient_egyptian_multiplication.c

#include <stdio.h>

int multiply_like_an_egyptian(int first, int second) { 
        int n;
        int o;
        if(first < second) { 
                n = second; o = first;
        } else { 
                n = first; o = second;
        } 
        static int n_powers[32];
        static int o_powers[32];
        int a_size = 64;
        int n_x = 1;
        int o_x = o;
        n_powers[a_size] = 1;
        o_powers[a_size] = o;
        int i = a_size - 1;
        while(n_x < n){
                n_powers[i] = n_x + n_x;
                o_powers[i] = o_x + o_x;
                n_x += n_x;
                o_x += o_x;
                //printf("%d %d %d \n", i, n_powers[i], o_powers[i]);
                i--;
        } 
        int l = n - n_powers[i];
        int s = 0;
        while(i <= a_size){
                int n_p = n_powers[i];
                int o_p = o_powers[i];
                //printf("%d %d %d %d\n", n_p, l, s, o_p);
                if(n_p <= l){
                        s += o_powers[i];
                        l = l - n_p;
                } 
                i++;
        } 
        return s;
}

int main()
{
        int result = multiply_like_an_egyptian(5, 5);
        printf("%d\n", result);
}