Manipulate bits

#include <iostream>

using std::cout;
using std::endl;

#define     MAX_COLUMNS 3
#define     MAX_ROWS    3
#define     MAX_BITS    3

void move_down(int m[MAX_COLUMNS][MAX_ROWS], int x, int y) {

    static int last[MAX_ROWS]   =  { -1 };
    static int p[MAX_ROWS]      =  { 0 };
    static int n[MAX_ROWS]      =  { 0 };

    if(last[x + n[x]] == -1)
        last[x + n[x]] = m[x + n[x]][y];
    else
        m[x + n[x]][y] = last[x + n[x]];

    if(p[x + n[x]] == MAX_BITS) {
        m[x + n[x]][y] = last[x + n[x]];
        p[x + n[x]] = 0;
        n[x] ++;
    }

    m[x + n[x]][y] |= (0b1 << p[x + n[x]]);
    p[x + n[x]] ++;

}

void print_m(int m[MAX_COLUMNS][MAX_ROWS]) {

    int y;

    for(int x = 0; x < MAX_COLUMNS; x++) {

        for(y = 0; y < MAX_ROWS; y++) {
            cout << m[x][y] << ", ";
        }
        cout << endl;
    }

}

int main()
{
    /*
    int matrix[MAX_COLUMNS][MAX_ROWS] = {
        {0b001, 0b010, 0b011, 0b100, 0b101, 0b110},
        {0b010, 0b011, 0b100, 0b101, 0b110, 0b101},
        {0b011, 0b100, 0b101, 0b110, 0b101, 0b100},
        {0b100, 0b101, 0b110, 0b101, 0b100, 0b011},
        {0b101, 0b110, 0b101, 0b100, 0b011, 0b010},
        {0b110, 0b101, 0b100, 0b011, 0b010, 0b001}
    };
    */

    int matrix[MAX_COLUMNS][MAX_ROWS] = { 0 };

    for(int a = 0; a < 6; a++) {

        move_down(matrix, 0, 0);
        print_m(matrix);
        cout << endl << endl;
    }


    int
        a = 0b0001,
        b = 0b0101,
        c = 0b1000;

    cout << (a & b) << endl;
    cout << (a | b) << endl;
    cout << (a ^ b) << endl;
    cout << (a & 0b1) << endl;
    cout << (b & 0b101) << endl;
    cout << (b & (0b1 << 2) ) << endl;
    cout << (c & (0b1 << 3) ) << endl;

    cout << "Ola!" << endl;

    return 0;
}