P88905: Producte de matrius qualssevol

#include <iostream>
#include <vector>
using namespace std;

typedef vector<int> Fila;
typedef vector<Fila> Matriu;

Matriu producte(const Matriu&a, const Matriu&b) {
    int p = a.size();
    int q = a[0].size();
    int r = b[0].size();
    Matriu mat(p, Fila(r, 0));
    for (int i = 0; i < p; ++i) {
        for (int j = 0; j < r; ++j) {
            for (int k = 0; k < q; ++k) {
                mat[i][j] += a[i][k]*b[k][j];
            }
        }
    }
    return mat;
}