getAccessibleCells

function getAccessibleCells (start, mp) {
    var accessibleCells = [];
    var cellsToAnalyse = [start];
    var newCells = [];

    for (var i = 1; i <= mp; i++) {
        for (var cell in cellsToAnalyse) {
            for (var neighbor in neighborsCells[cell]) {
                if (accessibleCells[neighbor] == null) {
                    accessibleCells[neighbor] = i;
                    push(newCells, neighbor);
                }
            }
        }
        cellsToAnalyse = newCells;
    }

    return accessibleCells;
}