import java.util.*;

public class Methods {
    // Write a method called digitSum that takes an integer n as a
    // parameter and that returns the sum of the digits of n.  Assume
    // that n is >= 0.
    public static int digitSum(int n) {
        int sum = 0;
        while (n > 0) {
            sum += n % 10;
            n = n / 10;
        }
        return sum;
    }

    // Write a method called roll7 that simulates the rolling of two dice
    // until their sum is equal to 7.  The method should print each roll
    // and its sum and show a count of how many rolls it took to get to
    // 7, as in:
    //     3 + 5 = 8
    //     2 + 1 = 3
    //     1 + 4 = 5
    //     3 + 4 = 7
    //     sum of 7 after 4 rolls
    // You may assume that an import on java.util is included in the
    // program so that you can construct a Random object.  You must
    // exactly reproduce the format of this sample execution.
    public static void roll7() {
        Random r = new Random();
        int sum = 0;
        int count = 0;
        while (sum != 7) {
            count++;
            int roll1 = r.nextInt(6) + 1;
            int roll2 = r.nextInt(6) + 1;
            sum = roll1 + roll2;
            System.out.println(roll1 + " + " + roll2 + " = " + sum);
        }
        System.out.println("sum of 7 after " + count + " rolls");
    }

    // Write a method called min that takes three integers as parameters
    // and that returns the minimum of the three values.
    public static int min(int x, int y, int z) {
        if (x <= y && x <= z) {
            return x;
        } else if (y <= x && y <= z) {
            return y;
        } else {
            return z;
        }
        // could have been written in one line as:
        // return Math.min(Math.min(x, y), z);
    }

    // Write a method called hasOddDigit that takes an integer as a
    // parameter and that returns true if it has an odd digit, false if
    // it does not.  You may assume that n is greater than or equal to 0.
    public static boolean hasOddDigit(int n) {
        while (n > 0) {
            int digit = n % 10;
            if (digit % 2 != 0) {
                return true;
            } 
            n = n / 10;
        }
        return false;
    }

    // Write a method called stutter that takes a string as a parameter
    // and that returns a new string where each letter of the original
    // string has been replaced with two of that letter.  For example,
    // stutter("hello") should return "hheelllloo"
    public static String stutter(String s) {
        String response = "";
        for (int i = 0; i < s.length(); i++) {
            response = response + s.charAt(i) + s.charAt(i);
        }
        return response;
    }
}