matrix_multiplication.cpp

#include<iostream>
using namespace std;

int main(){
    int m,n,p,q;

    cout << "Enter row & coloumn number of first matrix: ";
    cin >> m >> n;
    int a[m][n];

    cout << "Enter row & coloumn number of second matrix: ";
    cin >> p >> q;
    int b[p][q];
    
    //in order to multiply two matrices coloumn no. of first matrix must be same with row no. of second matrix
    int result[m][q];

    if(n != p){
        cout<<"Matrices cannot be multiplied together"<<endl;
    }
    else{
        cout<<"Enter the first matrix: "<<endl;
        for(int i=0; i<m; i++){
            for(int j=0; j<n; j++){
                cin>>a[i][j];
            }
        }

        cout<<"Enter the second matrix: "<<endl;
        for(int i=0; i<p; i++){
            for(int j=0; j<q; j++){
                cin>>b[i][j];
            }
        }

        for(int i=0; i<m; i++){ //as the resultant matrix would be of m x q order
            for(int j=0; j<q; j++){
                int sum = 0;
                //calculate result
                for(int k=0; k<n; k++){   //or k<p
                    sum += a[i][k] * b[k][j];
                }
                result[i][j]=sum;
            }
        }

        //print the result
        cout<<"The resultant matrix is:"<<endl;
        for(int i=0; i<m; i++){
            for(int j=0; j<q; j++){
                cout<<result[i][j];
                cout<<"\t";
            }
            cout<<endl;
        }

    }

}