Sorting.java

Sorting.java

public class MainSort {
	public void print(int[] ar){
		for(int a : ar){
			System.out.print(a + " ");
		}
		System.out.println();
	}
	
	public void swap(int[] ar, int a, int b){
		int temp = ar[b];
		ar[b] = ar[a];
		ar[a] = temp;
	}
	
	public void insertionSort(int[] ar){
		for(int i = 1; i < ar.length; i++){
			for(int j = i; j > 0; j--){
				if(ar[j] < ar[j-1])swap(ar, j, j-1);
			}
		}
	}
	
	public void selectionSort(int[] ar){
		for(int i = 0; i < ar.length; i++){
			int min = i;
			for(int j = i+1; j < ar.length; j++){
				if(ar[j] < ar[min])min = j;
			}
			swap(ar, i, min);
		}
	}
	
	public void bubleSort(int[] ar){
		boolean swapped = true;
		for(;swapped;){
			swapped = false;
			for(int i = 1; i < 	ar.length; i++){
				if(ar[i-1] > ar[i]){
					swap(ar, i, i -1);
					swapped = true;
				}
			}
		}
	}
	
	public void quickSort(int[] ar){
		doQuickSort(ar, 0, ar.length-1);
	}
	
	private void doQuickSort(int[] ar, int low, int high){
		int i = low;
		int j = high;
		int piv = ar[(low + high)/2];
		
		for(;i <= j;){
			for(; ar[i] < piv;){
				i++;
			}
			
			for(; ar[j] > piv;){
				j--;
			}
			
			for(;i <= j;){
				swap(ar,i,j);
				i++;
				j--;
			}
		}
		if(low < j){
			doQuickSort(ar, low, j);
		if(i < high)
			doQuickSort(ar, i, high);
		}
	}
	
	public static void main(String[] args) {
		MainSort main = new MainSort();
		int[]ar = {5,4,3,2,1};
		main.quickSort(ar);
		main.print(ar);
	}
}