// This file contains some examples of methods that students might be asked to
// write for the midterm.

import java.util.*;

public class Methods2 {
    public static void main(String[] args) {
        int sum = digitSum(935);
        System.out.println("sum = " + sum);
    }

    // returns the sum of the digits of n (assumes n is not negative)
    public static int digitSum(int n) {
        int sum = 0;
        while (n > 0) {
            int digit = n % 10;
            n = n / 10;
            sum += digit;
        }
        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 static method called hasOddEvenDigit that takes an integer
    // n as a parameter and that returns true if n has both an odd digit
    // and an even digit and that returns false otherwise.  For example,
    // the call hasOddEvenDigit(68437) should return true because the
    // number has both odd digits (3 and 7) and even digits (6, 8, and 4).
    public static boolean hasOddEvenDigit(int n) {
        int evens = 0;
        int odds = 0;
        while (n > 0) {
            int digit = n % 10;
            n = n / 10;
            if (digit % 2 == 0) {
                evens++;
            } else {
                odds++;
            }
        }
        return evens > 0 && odds > 0;
    }

    // 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++) {
            char ch = s.charAt(i);
            response = response + ch + ch;
        }
        return response;
    }
}