Number Snake

#include <iostream>
#include <vector>
#include <stdlib.h>
#include <ctime>
using namespace std;
//1 - вверх
//2 - вправо
//3 - вниз
//4 - влево
bool isEmpty(int direction, int n, int m, int x, int y,vector<vector<int>> field) {
    switch (direction)
    {
    case 1:
        return (y - 1 >= 1) && (field[y - 2][x - 1] == 0);
        break;
    case 2:
        return (x + 1 <= m) && (field[y - 1][x] == 0);
        break;
    case 3:
        return (y + 1 <= n) && (field[y][x - 1] == 0);
        break;
    case 4:
        return (x - 1 >= 1) && (field[y - 1][x - 2] == 0);
        break;
    }
}
int newDirection(int direction) {
        switch (direction)
        {
        case 1:
            return 2;
            break;
        case 2:
            return 3;
            break;
        case 3:
            return 4;
            break;
        case 4:
            return 1;
            break;
        }
    }

int main()
{
    srand(time(NULL));
    int n;
    int m;
    cin >> n;
    cin >> m;
    int number = 1;
    int direction = 2;
    vector <vector<int>> field;
    field.resize(n);
    for (int i = 0; i < n; i++) {
        field[i].resize(m);
        for (int j = 0; j < m; j++) {
            field[i][j] = 0;
        }
    }
    int x = (rand() % (m - 1)) + 1;
    int y = (rand() % (n - 1)) + 1;

    while (number <= n * m) {
        field[y-1][x-1] = number;
        if (!isEmpty(direction, n, m, x, y, field)) {
            direction = newDirection(direction);
        }
        switch (direction) {
        case 1:
            y--;
            break;
        case 2:
            x++;
            break;
        case 3:
            y++;
            break;
        case 4:
            x--;
            break;
        }
        number++;
    }
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cout << field[i][j] << ' ';
        }
        cout << endl;
    }
    system("pause");

}