用1、2、3、3、4、5这六个数字，用java写一个程序，打印出所有不同的排列 要求："4"不能在第三位，"3"与"5"不能相连。

用1、2、3、3、4、5这六个数字，用java写一个程序，打印出所有不同的排列 要求："4"不能在第三位，"3"与"5"不能相连。

递归：

 

import java.util.ArrayList;
import java.util.List;

public class Test1 {
	 public static void f(String in, ArrayList al) {
	        if (al.size() == 1) {
	            String tmp = in ;
	            if (!(tmp.contains("35") || tmp.contains("53") || tmp.indexOf('4') == 2)) {
	                System.out.println(tmp);
	            }
	        } else {
	            ArrayList hsc = (ArrayList) al.clone();
	            if (in.length() != 0) {
	                hsc.remove(in.substring(in.length() - 1));
	            }
	            for (Object i : hsc) {
	                f(in + i, hsc);
	            }
	        }
	    }
	 public static void ff(String in, ArrayList<String> al){
		 if (al.size()==1) {
			if (!(in.contains("35")||in.contains("53")||in.indexOf("4")==2)) {
				System.out.println(in);
			}
		} else {
			ArrayList<String> hsc=(ArrayList<String>) al.clone();
			if (in.length()!=0) {
				hsc.remove(in.substring(in.length()-1));
			}
			for (String string : hsc) {
				ff(in+string,hsc);
			}
		}
	 }
	public static void main(String args[]) {
		  ArrayList<String> al = new ArrayList<String>();
	        al.add("1");
	        al.add("2");
	        al.add("3");
	        al.add("4");
	        al.add("5");
	        al.add("6");
	        f("", al);
	}
}

 循环遍历：

 

import java.util.ArrayList;

public class Test2 {
	public static void main(String args[]) {
		int[] nums = { 1, 2, 2, 3, 4, 5 };
		for (int i = 0; i < nums.length; i++) {
			for (int j = 0; j < nums.length; j++) {
				if (i == j || (nums[i] * nums[j] == 15))
					continue;
				for (int k = 0; k < nums.length; k++) {
					if (k == i || k == j || (nums[j] * nums[k] == 15)
							|| nums[k] == 4) {
						continue;
					}
					for (int m = 0; m < nums.length; m++) {
						if (m == k || m == i || m == j
								|| (nums[k] * nums[m] == 15)) {
							continue;
						}
						for (int n = 0; n < nums.length; n++) {
							if (n == m || n == k || n == i || n == j
									|| (nums[m] * nums[n] == 15)) {
								continue;
							}
							for (int l = 0; l < nums.length; l++) {
								if (l == n || l == m || l == k || l == j
										|| l == i || (nums[n] * nums[l] == 15)) {
									continue;
								}
								System.out.println(nums[i] + "" + nums[j] + ""
										+ nums[k] + "" + nums[m] + "" + nums[n]
										+ "" + nums[l]);
							}
						}
					}
				}
			}
		}
	}
}