数据结构树与二叉树（4）树的括号表示法

#include <iostream>
#include <stack>
#include <queue>
 
using namespace std;
 
struct Node {
	char name;
	Node* child;
	Node* brother;
	Node(char str, Node* ch = nullptr, Node* br = nullptr) {
		name = str;
		child = ch;
		brother = br;
	}
};
 
 
int main() 
{
	string str;
	cin >> str;
 
	int mark = 0;
	stack<Node*> s;
	queue<Node*> q;
	Node* root;
 
	for (int i = 1; i < str.length() - 1; i++) {
		switch (str[i]) {
			case '(':
				mark = 1;
				break;
			case ')':
				s.pop();
				break;
			case ',':
				mark = 2;
				break;
			default:
				Node* p = new Node(str[i]);
				if (s.empty()) root = p;
				if (mark == 1)
				{
					Node* t = s.top();
					t->child = p;
				}
 
				if (mark == 2) 
				{
					Node* t = s.top();
					t->brother = p;
					s.pop();
				}
				s.push(p);
		}
	}
	q.push(root);
 
	while (!q.empty()) {
		Node* t = q.front();
		cout << t->name;
		q.pop();
		if (t->child != nullptr) {
			t = t->child;
			while (t != nullptr) {
				q.push(t);
				t = t->brother;
			}
		}
	}
	return 0;
}