Coderbyte Problems for Reshad

CoinDeterminer.java

import java.util.*; 
import java.io.*;

class Function {  
	String CoinDeterminer(int sum) {
		int[] coins = {1,5,7,9,11};
		List<Integer> knapsack = new ArrayList<Integer>();
		knapsack.add(0);
		knapsack.add(1);
		
		for (int i = 2; i <= sum; i++) {
			int minCoin = 11;
			int minValue = i;
			for (int denom : coins) {				
				if (denom <= i && knapsack.get(i - denom) < minValue) {
					int nextValue = knapsack.get(i - denom);
					minCoin = denom;
					minValue = nextValue;
				}				
			}
			knapsack.add(i, knapsack.get(i - minCoin) + 1);
		}
		return knapsack.get(sum).toString();
	}
}

public class CoinDeterminer {
	public static void main (String[] args) {  
		Function f = new Function();
		System.out.println(f.CoinDeterminer(35));
	}
} 

FibonacciChecker.java

import java.util.*; 
import java.io.*;

class Function {  
	
	static boolean FibEquations(int x, boolean sign) {
		double signed = sign ? 4.0 : -4.0;
		double val = Math.sqrt(5.0 * Math.pow(x, 2) + signed);
		return val % 1 == 0 ? true : false;
	}
	
	String FibonacciChecker(int num) {
		return (FibEquations(num, true) || FibEquations(num, false)) ? "yes" : "no";
	}
}

public class FibonacciChecker {
	public static void main (String[] args) {  
		Function f = new Function();
		System.out.println(f.FibonacciChecker(986));
	}
} 

MostFreeTime.java

import java.util.*; 
import java.io.*;

class Function {  
	String MostFreeTime(String[] slots) { 
		List<Integer> beginnings = new ArrayList<Integer>();
		List<Integer> endings = new ArrayList<Integer>();
		
		for (String slot : slots) {
			String[] split = slot.split("-");
			for (int index = 0; index <= 1; index++) {
				String s = split[index];
				String[] hm = s.split(":");
				int hours = Integer.parseInt(hm[0]);
				int minutes = Integer.parseInt(hm[1].substring(0, 2));
				String ampm = hm[1].substring(2, 4);
				if (ampm.equals("PM") && hours >= 1 && hours <= 11) {
					hours = hours + 12;
				} else if (ampm.equals("AM") && hours == 12) {
					hours = hours - 12;
				}
				int timeInMinutes = hours * 60 + minutes;
				if (index == 0) {
					beginnings.add(timeInMinutes);
				} else {
					endings.add(timeInMinutes);
				}
			}
		}
		Collections.sort(beginnings);
		Collections.sort(endings);
		int largest = 0;
		for (int i = 1; i < beginnings.size(); i++) {
			int diff = beginnings.get(i) - endings.get(i - 1);
			if (diff > largest) {
				largest = diff; 
			}
		}
		return String.format("%02d", new Integer(largest / 60)) + ":" + String.format("%02d", new Integer(largest % 60));
	}      
}

public class MostFreeTime {
	public static void main (String[] args) {  
		Function f = new Function();
		String[] slots =  {"06:00AM-08:00PM","05:00AM-05:45AM","08:02PM-08:04PM","08:10PM-09:00PM","09:09PM-09:11PM"};
		System.out.println(f.MostFreeTime(slots));
	}
} 

NumberSearch.java

import java.util.*; 
import java.io.*;

class Function {  
	String NumberSearch(String str) {
		char[] chars = str.toCharArray();
		float letters = 0;
		float sum = 0;
		for (Character c : chars) {
			if (Character.isLetter(c)) {
				letters += 1;
			} else if (Character.isDigit(c)) {
				sum += Character.digit(c, 10);
			}
		}
		return (new Integer(Math.round(sum / letters))).toString();
	}
}

public class NumberSearch {
	public static void main (String[] args) {  
		Function f = new Function();
		System.out.println(f.NumberSearch("Hel4 e4ee"));
	}
}