/**
* childPathList里面的每个元素为一个Stack<Integer>，栈顶存放了路径的起始节点，栈底则 存放了终止节点, 该方法用于getPaths(catId)之中
*
* @param childPathList
*/
private List<Stack<Integer>> walkUp(List<Stack<Integer>> childPathList) {
List<Stack<Integer>> results = new LinkedList<>();
for (Stack<Integer> subPath : childPathList) {
int currentId = subPath.peek();
int depth = getDepth(currentId);
if (depth <= 1) {
results.add(subPath);
} else {
Set<Integer> parentIds = getParentIds(currentId);
for (int parentId : parentIds) {
Stack<Integer> path = (Stack<Integer>) subPath.clone();
path.push(parentId);
results.add(path);
}
}
}
return results;
}
