C++实现AOE网中的关键路径算法(邻接表存储)

Posted 2021-06-29 Wecccccccc

代码如下:

#include <iostream>
#include <stack>
#include <string>
using namespace std;
const int N = 10010;
using vnodeType = int;


typedef struct Node
{
	int adj;
	int tw;//弧的时间权值
	Node *next;
}Node;

typedef struct Vnode
{
	vnodeType v;//存储图中结点的信息
	int in;
	Node *first;

}Vnode;

class AoeGraph
{

public:


	AoeGraph()
	{
		memset(adjlist, 0, sizeof(adjlist));
		memset(ve, 0, sizeof(ve));
		memset(tpord, 0, sizeof(tpord));
		memset(vl, 0, sizeof(vl));
	}

	void createGraph()
	{
		int n, m;
		cin >> n >> m;
		vn = n;
		en = m;
		for (int i = 0; i < vn; i++)
		{
			cin >> adjlist[i].v;
			adjlist->first = nullptr;
		}
		for (int i = 0; i < m; i++)
		{
			int x, y,w;
			cin >> x >> y>>w;
			Node *p = new Node;
			p->adj = y;
			p->tw = w;
			p->next = adjlist[x].first;
			adjlist[x].first = p;
		}
	}

	void findIn()
	{
		for (int i = 0; i < vn; i++)
		{
			adjlist[i].in = 0;
		}
		for (int i = 0; i < vn; i++)
		{
			for (Node *p = adjlist[i].first; p; p = p->next)
			{
				adjlist[p->adj].in++;
			}
		}
	}

	bool TopOrder() 
	{
		stack<int>s;
		findIn();
		for (int i = 0; i < vn; i++)
		{
			if (adjlist[i].in == 0)
			{
				s.push(i);
			}
		}
		int n = vn;
		int cnt = 0;
		while (!s.empty())
		{
			int xx = s.top();
			s.pop();
			n--;
			//tpord[cnt++] = adjlist[xx].v;
			tpord[cnt++] = xx;
			for (Node *p = adjlist[xx].first; p; p = p->next)
			{
				int yy = p->adj;
				adjlist[yy].in--;
				if (adjlist[yy].in == 0)
				{
					s.push(yy);
				}
				if (ve[xx] + p->tw > ve[yy])
				{
					ve[yy] = ve[xx] + p->tw;
				}
			}
		}
		if (!n) return true;
		else return false;
	}


	bool Criticalpath()
	{
		int cnt = vn;
		if (!TopOrder()) return false;
		for (int i = 0; i < vn; i++)
		{
			vl[i] = ve[vn - 1];//初始化顶点事件的最迟发生时间
		}
		for (int i = cnt-1; i >= 0; i--)
		{
			int xx = tpord[i];
			for (Node *p = adjlist[xx].first; p; p = p->next)
			{
				int yy = p->adj;
				if (vl[yy] - p->tw < vl[xx])
				{
					vl[xx] = vl[yy] - p->tw;
				}
			}
		}
		int e = 0;
		int l = 0;
		for (int i = 0; i < vn; i++)
		{
			for (Node *p = adjlist[i].first; p; p = p->next)
			{
				int k = p->adj;
				e = ve[i];
				l = vl[k] - p->tw;
				if (e == l) cout << i << " -> " << k<<endl;
			}
		}
		return true;
	}


private:
	Vnode adjlist[N];
	int vn;
	int en;
	int tpord[N];
	int ve[N];
	int vl[N];
};

int main() 
{
	AoeGraph g;
	g.createGraph();
	g.Criticalpath();
	return 0;
}

测试结果: