16.1.java

public class FlipFlop {
   public static String findFlipFlop(int testNm) {
      String retString = "";
      for (int i = 1; i <= testNm; i++) {
         boolean three = i % 3 == 0;
         boolean five = i % 5 == 0;
         if (three || five) {
            if (three) {
               retString += "Flip";
            }
            if (five) {
               retString += "Flop";  
            }
         } else {
            retString += "Nah";  
         }
            
         retString += ((testNm != i) ? " " : "");
      }
      return retString;
   }
   
   public boolean checkForFlop(int testNm) {
      return findFlipFlop(testNm).indexOf("Flop") > -1;
   }
}

16.2.java

public class ArrayMinMax {
   public static int findMax(int[] numberArray) {
      int max = 0;
      for (int num : numberArray) {
         if (num > max) {
            max = num;  
         }
      }
      return max;
   }
   
   public static int findMin(int[] numberArray) {
      int min = numberArray[0];
      for (int num : numberArray) {
         if (num < min) {
            min = num;  
         }
      }
      return min;
   }

   public int totalMaxMin(int[] numberArray) {
      int min = numberArray[0];
      int max = 0;
      for (int num : numberArray) {
         if (num < min) {
            min = num;  
         }
         if (num > max) {
            max = num;  
         }
      }
      return max + min;
   }
}

16.3.java

import java.util.ArrayList;

public class NumberProperties {
   // Constructor not shown
 
   public ArrayList<Integer> factorsOf(int testNum) {
      ArrayList<Integer> factors = new ArrayList<Integer>();
      for (int i = 1; i <= testNum; i++) {
         if (testNum % i == 0) {
            factors.add(i);  
         }
      }
      return factors;
   }

   public int[] multiplesIn(int testNum, int start, int finish) {
      int[] multiples = new int[finish-start];
      for (int i = start; i <= finish; i++) {
         multiples[start-i] = testNum * i;  
      }
      return multiples;
   }
}

16.4.java

import java.util.ArrayList;

public class NutsNBolts {
   public int sumArray(int[] numberArray, int start, int end) {
      int total = 0;
      for (int i = start; i <= end; i++) {
         total += numberArray[i];  
      }
      return total;
   }
         
   public int productArray(int[] numberArray, int start, int end) {
      int total = 1;
      for (int i = start; i <= end; i++) {
         total *= numberArray[i];
      }
      return total;
   }
         
   public boolean isIncreasing(int[] numberArray, int start, int end) {
      int last = 0;
      for (int i = start; i < end; i++) {
         if (last > numberArray[i]) {
            return false;
         }
         last = numberArray[i];  
      }
      return true;
   }
         
   public int[] getDivisibles(int[] numberArray, int start, int end) {
      ArrayList<Integer> retList = new ArrayList<Integer>();
      if (isIncreasing(numberArray, start, end)) {
         for (int num : numberArray) {
            if (num % 3 == 0) retList.add(num);
         }
      } else {
         for (int num : numberArray) {
            if (num % 2 == 0) retList.add(num);  
         }
      }
      int[] retArray = new int[retList.size()];
      for (int i = 0; i < retList.size(); i++) {
         retArray[i] = retList.get(i);  
      }
      return retArray;
   }
         
   public int concatenateArray(int[] numberArray) {
      int ret = 0;
      for (int i = 0; i < numberArray.length; i++) {
         ret += numberArray[numberArray.length-i-1]*(int)(Math.pow(10.0, (double)i));  
      }
      return ret;
   }
}

16.5.java

public class TimeGaps {
   public int getShortestTimeJump(int[] startYears, int[] endYears) {
      int shortest = Integer.MAX_VALUE;
      for (int i = 0; i < startYears.length; i++) {
         int val = endYears[i] - startYears[i];
         if (val < shortest) shortest = val;
      }
      return shortest;
   }
         
   public int getGalacticID(String galacticName) {
      final String ALPHABET = " abcdefghijklmnopqrstuvwxyz";
      int galacticID = 0;
      for (char c : galacticName.toLowerCase().toCharArray()) {
         galacticID += ALPHABET.indexOf(c);
      }
      return galacticID;
   }
}

16.6.java

import java.util.Random;
 
public class Dice {
   private Random dice = new Random();
 
   public Dice() { }

   public int diceRoll() {
      return dice.nextInt(6) + 1;
   }

   public double averageDiceRoll(int numberOfRolls) {
      double ret = 0.0;
      for (int i = 0; i < numberOfRolls; i++) {
         ret += (double) this.diceRoll();
      }
      return ret/(double)numberOfRolls;
   }
}