public class Solution {
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        ListNode head = new ListNode(0);
        ListNode handler = head;
        while(l1 != null && l2 != null) {
            if (l1.val <= l2.val) {
                handler.next = l1;
                l1 = l1.next;
            } else {
                handler.next = l2;
                l2 = l2.next;
            }
            handler = handler.next;
        }
        
        if (l1 != null) {
            handler.next = l1;
        } else if (l2 != null) {
            handler.next = l2;
        }
        
        return head.next;
    }
}

import java.io.File;
import java.io.IOException;
import java.util.Map;
import java.util.Scanner;
import java.util.TreeMap;

public class SimpleWordCounter {
    
    public static void main(String[] args) {
        try {
            File f = new File("ciaFactBook2008.txt");
            Scanner sc;
            sc = new Scanner(f);
            // sc.useDelimiter("[^a-zA-Z']+");
            Map<String, Integer> wordCount = new TreeMap<String, Integer>();
            while(sc.hasNext()) {
                String word = sc.next();
                if(!wordCount.containsKey(word))
                    wordCount.put(word, 1);
                else
                    wordCount.put(word, wordCount.get(word) + 1);
            }
            
            // show results
            for(String word : wordCount.keySet())
                System.out.println(word + " " + wordCount.get(word));
            System.out.println(wordCount.size());
        }
        catch(IOException e) {
            System.out.println("Unable to read from file.");
        }
    }
}

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		char[] variables = setVariables(in);
		int[] minTerms = setMinTerms(in);
		String[] binaryMinTerms = decimalToBinary(variables, minTerms);
		
		ArrayList<Group> groups = computeSuccessiveGroups(minTerms, binaryMinTerms);
		
		displayInput(variables, minTerms);
		printPIs(groups, variables);
	}
	
	private static char[] setVariables(Scanner in) {
		System.out.print("Enter the number of variables: ");
		int numVariables = in.nextInt();
		char[] variables = new char[numVariables];
		
		System.out.print("Enter each variable separated by spaces: ");
		for(int i = 0; i < numVariables; i++) {
			variables[i] = in.next().charAt(0);
		}
		return variables;
	}
	
	private static int[] setMinTerms(Scanner in) {
		System.out.print("Enter the number of min terms: ");
		int numMinTerms = in.nextInt();
		int[] minTerms = new int[numMinTerms];
		
		System.out.print("Enter each min term separated by spaces: ");
		for(int i = 0; i < numMinTerms; i++) {
			minTerms[i] = in.nextInt();
		}
		return minTerms;
	}
	
	private static String[] decimalToBinary(char[] variables, int[] minTerms) {
		String[] binaryMinTerms = new String[minTerms.length];
		for(int i = 0; i < minTerms.length; i++) {
			binaryMinTerms[i] = Integer.toBinaryString(minTerms[i]);
			if(binaryMinTerms[i].length() < variables.length) {
				String zeros = "";
				int len = binaryMinTerms[i].length();
				while(len < variables.length) {
					zeros = zeros.concat("0");
					len++;
				}
				binaryMinTerms[i] = zeros + binaryMinTerms[i];
			}
		}
		return binaryMinTerms;
	}
	
	private static void displayInput(char[] variables, int[] minTerms) {
		System.out.print("Function: f(");
		for(int i = 0; i < variables.length; i++) {
			if(i == variables.length-1)
				System.out.print(variables[i]);
			else
				System.out.print(variables[i] + ", ");
		}
		System.out.print(") = SIGMAm(");
		for(int i = 0; i < minTerms.length; i++) {
			if(i == minTerms.length-1)
				System.out.print(minTerms[i]);
			else
				System.out.print(minTerms[i] + ", ");
		}
		System.out.println(")");
	}
	
	private static ArrayList<Group> computeSuccessiveGroups(int[] minTerms, String[] binaryMinTerms) {
		ArrayList<Group> groups = new ArrayList<Group>();
		for(int i = 0; i < minTerms.length; i++)
			groups.add(new Group(Integer.toString(minTerms[i]), binaryMinTerms[i]));
		
		int sizeBeforeRemoval = 0, currentSize;
		while(sizeBeforeRemoval != groups.size()) {
			currentSize = groups.size();
			for(int i = 0; i < currentSize; i++) {
				for(int j = i+1; j < currentSize; j++) {
					if(differences(groups.get(i).binary, groups.get(j).binary) == 1) {
						String combinedBin = combineBinary(groups.get(i).binary, groups.get(j).binary);
						
						groups.get(i).grouped = true;
						groups.get(j).grouped = true;
						
						if(isUniqueBin(groups, combinedBin)) {
							String newTuple = groups.get(i).decimal + "," + groups.get(j).decimal;
							groups.add(new Group(newTuple, combinedBin));
						}
						else break;
					}
				}
			}
			
			sizeBeforeRemoval = groups.size();
			
			Iterator<Group> iter = groups.iterator();
			while(iter.hasNext()) {
				Group next = iter.next();
				if(next.grouped)
					iter.remove();
			}
		}
		return groups;
	}
	
	private static int differences(String a, String b) {
		int diff = 0;
		
		for(int i = 0; i < a.length(); i++)
			if(a.charAt(i) != b.charAt(i))
				diff++;
		
		return diff;
	}
	
	private static String combineBinary(String a, String b) {
		String combined = "";
		for(int i = 0; i < a.length(); i++) {
			if(a.charAt(i) != b.charAt(i))
				combined = combined.concat("-");
			else
				combined = combined.concat(Character.toString(a.charAt(i)));
		}
		return combined;
	}
	
	private static boolean isUniqueBin(ArrayList<Group> groups, String s) {
		for(int i = 0; i < groups.size(); i++)
			if(groups.get(i).binary.equals(s))
				return false;
		
		return true;
	}
	
	private static void printPIs(ArrayList<Group> groups, char[] variables) {
		System.out.println("Prime Implicants: ");
		for(int i = 0; i < groups.size(); i++)
			System.out.println(groups.get(i).decimal + " | " + binaryToMinTerm(variables, groups.get(i).binary));
	}
	
	private static String binaryToMinTerm(char[] variables, String s) {
		String minTerm = "";
		
		for(int i = 0; i < s.length(); i++) {
			if(s.charAt(i) != '-') {
				if(s.charAt(i) == '0')
					minTerm = minTerm.concat(Character.toString(variables[i]) + "'");
				else
					minTerm = minTerm.concat(Character.toString(variables[i]));
			}
		}
		
		return minTerm;
	}
}

public static void enu2ecefCov(GMatrix ecefCov, GMatrix enuCov, LLA refLLA) {
    double lambda = refLLA.longitude;
    double phi = refLLA.latitude;
    
    GMatrix R = new GMatrix(6, 6);
    GMatrix Rt = new GMatrix(6, 6);
    GMatrix tmp1 = new GMatrix(6, 6);
    GMatrix tmp2 = new GMatrix(6, 6);
    
    R.setElement(0, 0, -Math.sin(lambda));
    R.setElement(0, 1, -Math.sin(phi)*Math.cos(lambda));
    R.setElement(0, 2, Math.cos(phi)*Math.cos(lambda));
    R.setElement(1, 0, Math.cos(lambda));
    R.setElement(1, 1, -Math.sin(phi)*Math.sin(lambda));
    R.setElement(1, 2, Math.cos(phi)*Math.sin(lambda));
    R.setElement(2, 0, 0);
    R.setElement(2, 1, Math.cos(phi));
    R.setElement(2, 2, Math.sin(phi));
    R.setElement(3, 3, -Math.sin(lambda));
    R.setElement(3, 4, -Math.sin(phi)*Math.cos(lambda));
    R.setElement(3, 5, Math.cos(phi)*Math.cos(lambda));
    R.setElement(4, 3, Math.cos(lambda));
    R.setElement(4, 4, -Math.sin(phi)*Math.sin(lambda));
    R.setElement(4, 5, Math.cos(phi)*Math.sin(lambda));
    R.setElement(5, 3, 0);
    R.setElement(5, 4, Math.cos(phi));
    R.setElement(5, 5, Math.sin(phi));

    Rt.transpose(R);
    tmp1.mul(enuCov, R);
    ecefCov.mul(Rt, tmp1);
}

import java.util.Arrays;
 
public class QuickSortMain {
 
    private static int array[];
 
    public static void sort(int[] arr) {
 
        if (arr == null || arr.length == 0) {
            return;
        }
        array = arr;
        quickSort(0, array.length-1);
    }
 
    private static void quickSort(int left, int right) {
 
        int i = left;
        int j = right;
        // find pivot number, we will take it as mid
        int pivot = array[left+(right-left)/2];
 
        while (i <= j) {
            /**
             * In each iteration, we will increment left until we find element greater than pivot
             * We will decrement right until we find element less than pivot
             */
            while (array[i] < pivot) { i++; } while (array[j] > pivot) {
                j--;
            }
            if (i <= j) {
                exchange(i, j);
                //move index to next position on both sides
                i++;
                j--;
            }
        }
        // call quickSort() method recursively
        if (left < j)
            quickSort(left, j);
        if (i < right)
            quickSort(i, right);
    }
 
    private static void exchange(int i, int j) {
        int temp = array[i];
        array[i] = array[j];
        array[j] = temp;
    }
 
    public static void main(String a[]){
        int[] input = {33,21,45,64,55,34,11,8,3,5,1};
        System.out.println("Before Sorting : ");
        System.out.println(Arrays.toString(input));
        sort(input);
        System.out.println("==================");
        System.out.println("After Sorting : ");
        System.out.println(Arrays.toString(array));
 
    }
}

public static String addBinary(){
 // The two input Strings, containing the binary representation of the two values:
    String input0 = "1010";
    String input1 = "10";

    // Use as radix 2 because it's binary    
    int number0 = Integer.parseInt(input0, 2);
    int number1 = Integer.parseInt(input1, 2);

    int sum = number0 + number1;
    return Integer.toBinaryString(sum); //returns the answer as a binary value;
}