SW adv楼栋摆列方式(DFS+照相)

import java.io.FileInputStream;
import java.util.Arrays;
import java.util.Scanner;
/**
 * 题目大意：给定测试用例个数T,N栋建筑物，N层建筑物的层高为N，建筑物在一条直线上，
 * 给出从直线两端看建筑物图形，求建筑物的排列方式有几种
 */
public class Soution2 {
	static int T,N,count;
	static int[] left,right;
	static boolean[] flag;
	static int[] low;
	public static void main(String[] args) throws Exception {
		System.setIn(new FileInputStream("src\\demo\\1.txt"));
		Scanner sc = new Scanner(System.in);
		T = sc.nextInt();
		for (int test_case = 1; test_case <= T; test_case++) {
			N = sc.nextInt();
			count = 0;
			left = new int[N];
			right = new int[N];
			low = new int[N];
			flag = new boolean[N+1];
			for (int i = 0; i <N; i++) {
				left[i] = sc.nextInt();
			}
			for (int i = 0; i <N; i++) {
				right[i] = sc.nextInt();
			}
			System.out.printf("input-->%d\n", N);
			System.out.printf("input-->%s \n",Arrays.toString(left));
			System.out.printf("input-->%s \n",Arrays.toString(right));
			System.out.println("====================");
			dfs(0);
			System.out.println(count);
		}
		
	}
	private static void dfs(int pos) {
		if (pos>=N) {
			int[]  leftpic = getphoto(low,"left");
			int[]  rightpic = getphoto(low,"right");
			
//			System.out.printf("-low:%s,left:%s，right:%s\n", Arrays.toString(low), Arrays.toString(leftpic),
//					Arrays.toString(rightpic));
			boolean compareLeft = compare(leftpic,left);
			boolean compareright = compare(rightpic,right);
			
//			System.out.printf("-low:%s,left:%s，right:%s,Bleft:%s,Bright:%s\n", 
//					Arrays.toString(low), 
//					Arrays.toString(leftpic),
//					Arrays.toString(rightpic),
//					compareLeft,
//					compareright
//					);
//			
			if(compareLeft&&compareright) {
				count++;
			}
			return;
		}
		for(int i=1;i<=N;i++) {
			if(flag[i]==false) {
				low[pos] = i;
				flag[i] = true;
				dfs(pos+1);
				flag[i] = false;
			}
		}
		
	}
	/**
	 * 比较两个数组是否相等
	 * @param date
	 * @param targer
	 * @return
	 */
	private static boolean compare(int[] date, int[] targer) {
		if(Arrays.toString(date).equals(Arrays.toString(targer))) {
			return true;
		}
		return false;
	}
	/**
	 * 得到建筑物摆列low的照相数组
	 * @param low 
	 * @param dir left从左边看，right从右边看
	 * @return
	 */
	private static int[] getphoto(int[] low,String dir) {
		int[] photo = new int[N];
		int start = 0;
		if("left".equals(dir)) {
			for (int i = 0; i <N; i++) {
				for (int j = start; j < low[i]; j++) {
					photo[j] = low[i];
				}
				start = Math.max(start, low[i]);
			}
		}else {
			for (int i = N-1; i>=0; i--) {
				for (int j = start; j < low[i]; j++) {
					photo[j] = low[i];
				}
				start = Math.max(start, low[i]);
				
			}
		}
		return photo;
	}
	
}