arrayutils

package sorting;

public class ArrayUtils {
	
	public static boolean isSorted(int[] in){
		for(int i = 0; i<in.length-1; i++){
			if(in[i+1] < in[i]){
				return false;
			}
		}
		return true;
	}
	
	public static void printArray(int[] in){
		for(int i = 0; i<in.length; i++){
			System.out.print(in[i] + ",");
		}
		System.out.println();
	}
	
	//swaps elements at index a and b 
	public static void swap(int[] in, int indA, int indB){
		int temp = in[indA];
		in[indA] = in[indB];
		in[indB] = temp;
	}
}

bubblesort

package sorting;

import javax.management.timer.Timer;



public class BubbleSort {
	
	public static void sort(int[] in){
		for(int i = 0; i<in.length-1; i++){
			if(in[i+1] < in[i]){
				int temp = in[i];
				in[i] = in[i+1];
				in[i+1] = temp;
			}
		}
		if(!ArrayUtils.isSorted(in)){
			sort(in);
		}
	}
	

	
	//returns total time in ms that it takes the sort to occur
	public static long timedSort(int[] in){
		long a = System.currentTimeMillis();
		System.out.println(a);
		sort(in);
		long b = System.currentTimeMillis();
		System.out.println(b);
		return b-a;
	}
	
	public static void printSortInfo(int[] in){
		System.out.println("it took " + timedSort(in) + " ms to fully sort a list of " + in.length + " elements");
	}
	
	public static void main(String args[]){
		int[] inData = RandomGenerator.getData(3000, 1000);
		ArrayUtils.printArray(inData);
		printSortInfo(inData);
		ArrayUtils.printArray(inData);
	}
	/**
	 * for each element i
	 * 		compare to element i + 1
	 * 		if i + 1 < i
	 * 			swap i with i + 1
	 * if(unsorted)
	 * sort()
	 * 
	 */
}

quicksort

package sorting;

public class Quicksort {
	/**
	 * use final element as pivot
	 * 
	 * 
	 * @param args
	 */
	
	public static void partition(int[] in, int start, int size){
		int wall = start;
		size = size - 1;
		int pivot = start + size;
		
		for(int i = 0; i<size; i++){
			if(in[i] < in[pivot]){
				ArrayUtils.swap(in, wall, i);
				wall++;
			}
		}
		partition(in,start,start+wall);
		partition(in,start+wall,in.length);
	}
	
	public static void sort(int[] in){
		partition(in,0,in.length);
	}
	
	public static void main(String args[]){
		int[] inData = RandomGenerator.getData(3000, 1000);
		ArrayUtils.printArray(inData);
		sort(inData);
		ArrayUtils.printArray(inData);
	}
}

randgen

package sorting;

import java.util.Random;

public class RandomGenerator {
	public static int[] getData(int elements,int range){
		int[] random = new int[elements];
		Random r = new Random();
		for(int i = 0; i<random.length; i++){
			random[i] = r.nextInt(range);
		}
		return random;
	}
	
	public static boolean checkSort(int[] input){
		for(int i = 0; i<input.length-1; i++){
			if(input[i] > input[i+1]){
				return false;
			}
		}
		return true;
	}
}

selection sort

package sorting;

public class SelectionSort {

	
	/**
	 * for each element
	 * 		find lowest element
	 * 		add to the end of the sorted portion
	 * 		
	 */
	public static void sort(int[] in){
		int minIndex = 0;
		for(int i = 0; i<in.length-1; i++){
			//for each element 
			for(int k = i+1; k<in.length; k++){
				if(in[minIndex] > in[k]){
					minIndex = k;
				}
			}
			ArrayUtils.swap(in, i, minIndex);
			minIndex = i+1;
		}
	}
	
	public static void main(String args[]){
		int[] inData = RandomGenerator.getData(3000, 1000);
		ArrayUtils.printArray(inData);
		sort(inData);
		ArrayUtils.printArray(inData);
	}
}