Sharif Vai Task

#include <bits/stdc++.h>

#define read freopen("input.txt","r",stdin)
#define write freopen("output.txt","w",stdout)
#define dArray A[100][100]

using namespace std;

// print 3x4 matrix A
void printMatrix(double dArray, int r, int c) {
    for (int i = 0; i < r; i++) {
        for (int j = 0; j < c; j++) {
            cout << A[i][j] << "\t";
        }
        cout << endl;
    }
    cout << "====================" << endl << endl;
}

void divideRow(double dArray, int c, int R, double P) {
    for (int j = 0; j < c; j++) {
        A[R][j] /= P;
    }
}

void addRow(double dArray, int c, int R1, int R2, double V) {
    for (int j = 0; j < c; j++) {
        A[R2][j] += V * A[R1][j];
    }
}

void rowReduce(double dArray, int r, int c) {
    int R = 0;
    for (int j = 0; j < c; j++) {
        bool found = false;
        for (int i = R; i < r; i++) {
            if (A[i][j] != 0) {
                found = true;
                if (i != R) {
                    for (int k = 0; k < c; k++) {
                        swap(A[R][k],A[i][k]);
                    }
                }
                double P = A[R][j];
                divideRow(A, c, R, P);
                for (int k = R + 1; k < r; k++) {
                    double V = A[k][j];
                    addRow(A, c, R, k, -V);
                }
                R++;
                break;
            }
        }
        if (!found) {
            // all elements in column j are zero
            continue;
        }
        if (R == 3) {
            break;
        }
    }
}

// main function
int main() {

    read;
    //write;

    int r, c;
    //int a[100][100];
    //vector<vector<double> > A;
    double A[100][100];
    cin>>r>>c;

    for (int i = 0; i < r; i++){
        for (int j = 0; j < c; j++){
            cin>>A[i][j];
        }
    }

    /*
    double A[r][c];
    A[0][0] = 2; A[0][1] = 1; A[0][2] = 0; A[0][3] = 5;
    A[1][0] = 3; A[1][1] = 6; A[1][2] = 1; A[1][3] = 1;
    A[2][0] = 5; A[2][1] = 7; A[2][2] = 1; A[2][3] = 8;
    p34(A);
    */

    printMatrix(A, r, c);
    rowReduce(A, r, c);
    printMatrix(A, r, c);
    return 0;
}