/*************************************************************************

> File Name: MatrixProduct.cpp

> Author: Netcan

> Blog: https://netcan.github.io/

> Mail: netcan1996@gmail.com

> Created Time: 2021-08-16 20:24

************************************************************************/

#include <vector>

#include <numeric>

#include <iostream>

#include "Views.h"

using namespace std;

auto product(ranges::viewable_range auto&& lhs, ranges::viewable_range auto&& rhs) {

return lhs | views::transform([=](auto&& xrow) mutable {

return rhs | transpose | views::transform([=](auto&& wcol) {

return std::inner_product(xrow.begin(), xrow.end(),

wcol.begin(), 0);

});

});

};

int main(int argc, char** argv) {

{

auto X = views::iota(1, 2 * 3 + 1) | chunk(3);

auto W = views::iota(1, 2 * 3 + 1) | chunk(2);

// X * W

print_range(product(X, W));

cout << "\n";

}

{

vector X { // 3 x 4

vector{3, 1, 1, 4},

vector{5, -3, 2, 1},

vector{6, 2, -9, 5},

};

vector W { // 4 x 2

vector{4, 9}, vector{6, -8},

vector{9, 7}, vector{7, 6},

};

print_range(product(X, W), true);

cout << "\n";

}

return 0;

}