Сравнение коээфициентов

#include <iostream>
bool compare(int k1, int k2) {
    bool res;
    if (k1 == k2) res = true;
    else res = false;
    return res; }

int main() {
    int x1,x2,x3,x4,y1,y2,y3,y4, k1, k2, b1,b2;
    bool res, res2;
    std::cin >> x1 >> y1 >> x2 >> y2;
    std::cin >> x3 >> y3 >> x4 >> y4;
    k1 = (y1-y2)*(x3-x4);
    k2 = (y3-y4)*(x1-x2);
    b1 = (x3 - x4)*(y1*(x1 - x2) - x1*(y1 - y2));
    b2 = (x1 - x2)*(y3*(x3 - x4) - x3*(y3 - y4));
    res = compare(k1, k2);
    res2 = compare(b1, b2);
    std::cout << res <<' ' << res2;
    return 0;
}