import java.util.*;
/**
* @Author 59456
* @Date 2021/7/24
* @Descrip 解决离散或者相邻部门上下的问题,时间复杂度O(N)、空间复杂度O(1)
* @Version 1.0
*/
public class Solution {
static Short MOVE_UP = 1;
static Short MOVE_DOWN = 0;
static List<Long> idList = new ArrayList<>();
static Set<Long> idSet = new HashSet<>();
static List<DepartmentMoveDto> departmentMoveDtoList = new ArrayList<>();
static {
// 设置原始有序数据集
for(Long i=0L;i<10L;i++){
DepartmentMoveDto departmentMoveDto = new DepartmentMoveDto();
departmentMoveDto.setId(i);
departmentMoveDto.setSort(Short.valueOf(i.toString()));
departmentMoveDto.setSortIndex(Double.valueOf(i.toString()));
departmentMoveDtoList.add(departmentMoveDto);
}
// 设置需要移动的节点id
// 其中0、1是一个空气泡,5、6是另外一个空气泡
idList.add(0L);
idList.add(1L);
idList.add(5L);
idList.add(6L);
idList.add(9L);
}
// 逆向思考:另外的节点移动
public static void move(List<Long> idList,Short moveType,Long parentId){
if(null == idList || idList.isEmpty()){
return;
}
// 获取同级部门排序信息
// List<DepartmentMoveDto> departmentMoveDtoList = departmentDao.getDepartmentMoveDtoListByParentId(parentId);
idSet = new HashSet<>(idList);
if(MOVE_UP.equals(moveType)){
moveUp(departmentMoveDtoList ,idSet);
}else {
Collections.reverse(departmentMoveDtoList);
moveUp(departmentMoveDtoList ,idSet);
Collections.reverse(departmentMoveDtoList);
}
}
/**
* 专门针对上移设计(其实下移也是另外一个视角的上移)
* 核心思想聚焦需要移动节点,上方相邻的普通节点(本质也可以看做这些节点的向下冒泡)
* @param departmentMoveDtoList 部门移动信息
* @param idSet 需要移动的部门id
*/
private static void moveUp(List<DepartmentMoveDto> departmentMoveDtoList,Set<Long> idSet){
int length = departmentMoveDtoList.size();
for(int index = 0; index<length-1; index++){
DepartmentMoveDto departmentMoveDtoPre = departmentMoveDtoList.get(index);
Long idPre = departmentMoveDtoPre.getId();
DepartmentMoveDto departmentMoveDtoNext = departmentMoveDtoList.get(index+1);
Long idNext = departmentMoveDtoNext.getId();
// 如果当前不移动,下一个移动:交换
if (!idSet.contains(idPre) && idSet.contains(idNext)) {
DepartmentMoveDto departmentMoveDtoSwitch = departmentMoveDtoList.get(index);
departmentMoveDtoList.set(index, departmentMoveDtoList.get(index + 1));
departmentMoveDtoList.set(index + 1,departmentMoveDtoSwitch);
}
}
}
public static void main(String[] args) {
departmentMoveDtoList.forEach(entity->{
System.out.println(entity.toString());
});
System.out.println("hello world!");
// 部门下移
move( idList, new Short("0"), 0L);
departmentMoveDtoList.forEach(entity->{
System.out.println(entity.toString());
});
}
}