elab-hxb/src/main/java/utils/CalcYizhiArrayUtils.java

package utils;

import model.Room;
import model.template.Template;

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

/**
 * @author duh
 * @create 2018/7/25 14:53
 * @email duh@elab-plus.com
 **/
public class CalcYizhiArrayUtils {
    private List<Integer> roomLength;
    private List<Integer> oneAlignAllLength;
    private List<Integer> twoAlignAllShortLength;
    private List<Integer> twoAlignAllLongLength;
    public void calcYizhiWithOnlyOneTwoAlign(){
        int totalOneLenth = 0;
        for(int length : oneAlignAllLength){
            totalOneLenth += length;
        }
        int leftForTwo = roomLength.get(3) - totalOneLenth;
        if(leftForTwo>0){
            System.out.println("可以一字排，方案如下:");
        }
    }

    /**
     * 获取n个数的所有组合
     * @param n
     */
    public List<List<Integer>> getAllArrayList(int n){
        List<List<Integer>> arrayList = new ArrayList<>();
        if(n < 1){
            return arrayList;
        }else if(n==1){
            List<Integer> list = new ArrayList<>();
            list.add(n);
            arrayList.add(list);
            return arrayList;
        }
        arrayList = getAllArrayList(n-1);
        for(int index = arrayList.size() -1;index>=0;index--){
            List<Integer> list = arrayList.remove(index);
            for(int i = 0;i<n;i++){
                List<Integer> newList = new ArrayList<>();
                newList.addAll(list);
                newList.add(i,n);
                arrayList.add(newList);
            }
        }
        return arrayList;
    }

    /**
     * 排列数
     * @param n
     * @return
     */
    public int A(int n){
        if(n <= 0){
            return 0;
        }else if(n==1){
            return 1;
        }else {
            return n*A(n-1);
        }
    }
}