Matrix multiplication with threads

matrix_mul_thread.cpp

#include<iostream>
#include<thread>
#include<fstream>
using namespace std;

/*input
4 //number of matrix
2 2 //dimension
1 2
4 5
3 2
6 5
1 1
2 2
4 4
5 6
*/

class Matrix {
    private:
        int grid[100][100];

    public:

        void setValue(int r, int c, int value){
            this->grid[r][c] = value;
        }

        int getValue(int r, int c) {
            return this->grid[r][c];
        }
};


Matrix multiplyMatrix(Matrix m1, Matrix m2, int row, int col){

    Matrix result;
    for(int i=0;i<row;i++){
        for(int j=0;j<col;j++){
            int res = 0;
            for(int k=0;k<col;k++){
                res += m1.getValue(i,k) * m2.getValue(k,j);
            }
            result.setValue(i,j,res);
        }
    }

    return result;

}


void scanMat(Matrix m1, Matrix m2, int row, int col, int index){

    cout<<endl;
    cout<<"Thread index: "<<index<<endl;
    cout<<"Result (after multiplication): "<<endl;

    Matrix result = multiplyMatrix(m1, m2, row, col);

    for(int i=0;i<row;i++){
        for(int j=0;j<col;j++){
            cout<<result.getValue(i,j)<<" ";
        }
        cout<<endl;
    }
    cout<<endl;
}



int main(){

    int tests, row, col;
    ifstream cin("input_3.txt");
    cin>>tests>>row>>col;

    int val;
    Matrix matArr[tests];

    for(int i = 0;i < tests;i++) {
        for(int j=0;j<row;j++) {
            for(int k=0;k<col;k++){
                cin>>val;
                matArr[i].setValue(j,k,val);
            }
        }
    }

    //test print all matrix
    /*
        for(int i = 0;i < tests;i++){
        for(int j=0;j<row;j++){
            for(int k=0;k<col;k++){
                cout<<matArr[i].getValue(j,k)<<" ";
            }
            cout<<endl;
        }
    }
    */

    thread thArr[tests/2];
    int tCount = 0;
    for(int i=0;i<tests;i+=2){
        thArr[tCount] = thread(scanMat, matArr[i], matArr[i+1], row, col, tCount);
        tCount++;
    }

    //join with main thread
    for(int i=0;i<tCount;i++){
        thArr[i].join();
    }

    return 0;
}