import java.util.Random;

/**
 * Temps2D - exercise with 24 hourly temperature rows by N days (columns).
 * All methods are instance (non-static). Use Random to populate and analyze.
 *
 * Rows = hours [0..23]
 * Cols = days  [0..days-1]
 */
public class DailyTemps {

    private final int days;          // number of days (columns)
    private final int[][] temps;     // temps[hour][day]
    private final Random rand = new Random();

    /**
     * Construct a temps table with 24 rows (hours) and the given number of days.
     */
    public DailyTemps(int days) {
        this.days = days;
        this.temps = new int[24][days];
    }

    /**
     * Randomly populate the table.
     * Rule: pick an initial random temperature in [20,70]. Then go hour-by-hour,
     * day-by-day, choosing the next temp within +/-5 degrees of the previous temp.
     *
     * Traversal order: day 0..days-1, hour 0..23.
     *   - For the very first cell (hour=0, day=0), choose any random in [20,70].
     *   - Otherwise, choose a delta in [-5,5] and add to the previous cell's value.
     */
    public void randomPopulate() {
        int prev = randBetween(20, 70); // start with a moderate temp
        for (int d = 0; d < days; d++) {
            for (int h = 0; h < 24; h++) {
                int next = prev + randBetween(-5, 5);
                temps[h][d] = next;
                prev = next;
            }
        }
    }

    /**
     * Pretty-print a single day's temps on one line.
     */
    public void printDay(int day) {
        // TODO: print temps for the given day across all 24 hours.
    }

    /**
     * Print the table in a readable grid.
     * Example (2 days):
     * Hour 0:  71  73
     * Hour 1:  70  74
     * ...
     */
    public void printTemps() {
        // TODO Implement me!
    }

    /**
     * Return an array of the average temperature for each day.

     */
    public double[]  getAverageTemps() {
        // TODO Implement me!
        return null; // So it compiles.
    }

    /**
     * Return an array with the highest temperature for each day.
     */
    public int[] getHighestDailyTemps() {
        // TODO Implement me!
        return null; // So it compiles.
    }

    /**
     * Return an array with the lowest temperature for each day.
     */
    public int[] getLowestDailyTemps() {
        // TODO Implement me!
        return null; // So it compiles.
    }

    /**
     * Return an array with the difference between the low and high temperature for each day.
     */
    public int[] getDailyDegreeChange() {
        // TODO Implement me!
        return null; // So it compiles.
    }

    /**
     * Convenience: get the temperature at a specific hour/day.
     * If an invalid day/time is specified, return -100.
     */
    public int get(int hour, int day) {
        if (hour < 0 || hour >= 24) 
            return -100;
        if (day < 0 || day >= days) 
            return -100;
        return temps[hour][day];
    }

    public void set(int hour,int day, int temp) {
        if(hour>=0 && hour<24 && day>=0 && day<days) {
            temps[hour][day]=temp;
        }
    }

    private int randBetween(int lo, int hi) {
        // inclusive bounds
        return lo + rand.nextInt(hi - lo + 1);
    }

}