Method areAllEqual

java/0427-construct-quad-tree.java:30–40

(int row, int column, int n)

    }

    private boolean areAllEqual(int row, int column, int n) {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n; j++) {
                if (grid[row][column] != grid[row + i][column + j]) {
                    return false;
                }
            }
        }

        return true;
    }

}