MatrixMultiple.cc

#include <iostream>
#include <cmath>
#include <sstream>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <numeric>

int main()
{
  int n,m,l;
  std::cin >> n >> m >> l;

  int **matrix1 = new int*[n];
  for (int i=0;i<n;i++) {
    matrix1[i] = new int[m];
  }
  for (int i=0; i<n; i++) {
    for (int j=0; j<m; j++) {
        int num;
        std::cin >> num;
        matrix1[i][j] = num;
    }
  }

 int **matrix2 = new int*[m];
 for (int i=0;i<m;i++) {
   matrix2[i] = new int[l];
 }
 for (int i=0;i<m;i++) {
   for (int j=0;j<l;j++) {
     int num;
     std::cin >> num;
     matrix2[i][j] = num;
   }
 }


 long ** result = new long*[n];
 for (int i=0;i<n;i++) {
   result[i] = new long[l];
 }
 for (int i=0;i<n;i++) {
   for (int j=0;j<l;j++) {
     result[i][j] = 0;
   }
 }
 for (int i=0;i<n;i++) {
   for (int j=0;j<m;j++) {
     for (int k=0;k<l;k++) {
      result[i][k] += matrix1[i][j] * matrix2[j][k];
     }
   }
 }

 for (int i=0; i<n;i++) {
   for (int j=0;j<l;j++) {
     std::cout << result[i][j];
     if (j!=l-1) {
       std::cout << " ";
     }
   }
   std::cout << std::endl;
 }

  return 0;
}