翻饼子问题

public class Cake {

	private int[] mid_cakes;
	private int size;
	private int[] steps_result;
	private int[] steps_swap;
	private int min_steps;
	private int searchTimes;
	
	public Cake(int[] cakes){
		this.mid_cakes = cakes;
		size = cakes.length;
		steps_result = new int[size * 2];
		steps_swap = new int[size * 2];
		min_steps = 5*(size+1)/3;
	}

	public void run() throws Exception {
		search(0);
	}
	
	public void search(int step) throws Exception{
		searchTimes++;
		int total = step + lowCounts(mid_cakes);
		if(total >= min_steps){
			return;
		}
		if(isSorted(mid_cakes)){
			min_steps = step;
			for(int i=0; i<size; i++){
				steps_result[i] = steps_swap[i];
			}
			return;
		}
		for(int i=1; i<size; i++){
			reverse(i);
			steps_swap[step] = i;
			search(step+1);
			reverse(i);
		}
	}
	
	private void reverse(int pos){
		for(int i=0,j=pos; i<j; i++,j--){
			int temp = mid_cakes[i];
			mid_cakes[i] = mid_cakes[j];
			mid_cakes[j] = temp;
		}
	}
	
	public void output(){
		System.out.println("The min swap counts is : " + min_steps);

		System.out.println("The search times is : " + searchTimes);
		
		System.out.print("The swap steps is : ");
		for(int i=0; i<min_steps; i++){
			System.out.print(steps_result[i] + " ");
		}
		System.out.println("\r");
	}

	
	
	private boolean isSorted(int[] cakes){
		for(int i=0; i<cakes.length-1; i++){
			if(cakes[i] > cakes[i+1]){
				return false;
			}
		}
		return true;
	}
	private int lowCounts(int[] cakes){
		int count = 0;
		for (int i=0; i<cakes.length-2; i++){
			int pace = cakes[i] - cakes[i+1];
			if((pace != -1) && (pace != 1)){
				count++;
			}
		}
		return count;
	}
	
	/**
	 * @param args
	 */
	public static void main(String[] args) {
//		int[] cakes = {3,2,1,6,5,4,9,8,7,0};
		int[] cakes = {4,2,1,3};
		Cake cake = new Cake(cakes);
		
		try {
			cake.run();
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		cake.output();
	}

}