couting sort by column

    public static int[][] sortArrayByColumn(int column) {
        int[][] sortedArray = new int[M][3];
        int min = hotels[M - 1][column];
        int max = hotels[0][column];
        //find min and max values for histogram from current column
        for (int i = 1; i < M; i++) {
            if (hotels[i][column] < min) {
                min = hotels[i][column];
            } else if (hotels[i][column] > max) {
                max = hotels[i][column];
            }
        }
        //histogram length from min to max
        int[] hist = new int[max - min + 1];
        for (int i = 0; i < M; i++) {
            hist[hotels[i][column] - min]++;
        }

        hist[0]--;
        for (int i = 1; i < hist.length; i++) {
            hist[i] = hist[i] + hist[i - 1];
        }
        //min to max
        for (int i = M - 1; i >= 0; i--) {
            int index = hist[hotels[i][column] - min];
            sortedArray[index][column] = hotels[i][column];
            sortedArray[index][1] = hotels[i][1];
            sortedArray[index][0] = hotels[i][0];
        }
        return sortedArray;
    }