Check for Integral Inputs for Remainder Implementation

integrals_check_remainder.cpp

#include <iostream>
#include <cmath>
#include <vector>

int main() {
    std::vector<std::vector<int>> samples = { {-7, -3}, {-7, 3}, {-5, 3}, {3, -2}, {3, 2}, {7, 2}, {7, -2} };
    std::cout << "Output format: a rem b is: std::remainder, a % b in C++, output of torch impl, output modified impl\n";
    for(auto vec: samples) {
        int a = vec[0], b = vec[1];

        // PyTorch implementation for integers
        int out_torch = a % b;
        int intermediate = out_torch;
        if (out_torch != 0 && (out_torch < 0) != (b < 0)) out_torch += b;

        // Matches C++ output of std::remainder
        auto out_correct = a - b * static_cast<int>(std::nearbyint(static_cast<float>(a)/b));

        std::cout << a << " rem " << b << " is: " << std::remainder(a, b) <<  ", " <<
                intermediate << ", " << out_torch << ", " << out_correct << '\n';
    }
}