Parcurgere matrici

// Parcurgerea unei matrici
// a) afisare normala
// b) coloane de jos in sus
// c) elementele de pe contur

#include <iostream>
using namespace std;
int main()
{
    int i, j, m, n, a[100][100];
    cout << "Introduceti numarul de linii: ";
    cin >> n;
    cout << "Introduceti numarul de coloane: ";
    cin >> m;
    for(i = 1; i <= n; i++)
        for(j = 1; j <= m; j++) {
            cout << "a[" << i << "][" << j << "]=";
            cin >> a[i][j];
        }
    cout << endl << "Parcurgerea normala a matricei: \n";
    for(i = 1; i <= n; i++) {
        for(j = 1; j <= m; j++)
            cout << a[i][j] << " ";
        cout << endl;
    }
    cout << "\n\n\nParcurgerea pe coloane de jos in sus: \n";
    for(i = n; i >= 1; i--) {
        for(j = 1; j <= m; j++)
            cout << a[i][j] << " ";
        cout << endl;
    }
    cout << "\n\n\nParcurgerea elementelor de pe contur: \n";
    for(j = 1; j <= m; j++)
        cout << a[1][j] << " ";
    for(i = 2; i < n; i++)
        cout << a[i][m] << " ";
    for(j = m; j >= 1; j--)
        cout << a[n][j] << " ";
    for(i = n - 1; i > 1; i--)
        cout << a[i][1] << " ";
    return 0;
}