技術標籤：日常練習c++拓撲排序

必要的準備

• 有向無環圖才有拓撲排序。問題，如果判斷一個有向圖是否有環？點這裡
• 拓撲排序的背後是約束關係，優先排程的問題首先被考慮。簡單的，你應該先學習十進位制數字再研究數論。問題，如何得到拓撲排序呢？點這裡

拓撲排序API

• TopologicalSort(Digraph G) 建構函式
• bool isDAG() 是有向無環圖麼
• stack<int>* order()拓撲有序的節點

程式碼

#pragma once
#include"DirectedCycle.h"
#include"DepthFirstOrder.h"
 


class TopologicalSort
{
public:
	TopologicalSort(Digraph& G);

	bool isDAG() { return !m_order->empty(); }
	stack<int>* order() { return m_order; }
private:
	stack<int>* m_order=nullptr;
};

void testTopSort();

#include "TopologicalSort.h"

TopologicalSort::TopologicalSort
 
(Digraph& G)
{
	DirectedCycle cycleFinder(G);
	if (!cycleFinder.hasCycle()) {
		DepthFirstOrder* dfO=new DepthFirstOrder(G);
		m_order=dfO->getRePost();
	}
}

void testTopSort() {
	Digraph G("tinyDAG.txt");
	TopologicalSort topS(G);
	out(topS.isDAG()), hh;
	stack<int>* stk = topS.
 
order();
	while (!stk->empty()) {
		int x = stk->top();
		out(x);
		stk->pop();
	}
	hh;
}

tinyDAG.txt

13
15
2 3 
0 6 
0 1 
2 0 
11 12  
9 12  
9 10  
9 11 
3 5 
8 7 
5 4 
0 5 
6 4 
6 9 
7 6