大白-Dijksta模板

     这个模板更加直观。

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<vector>
#include<queue>
#include<cmath>
typedef long long ll;
using namespace std;
#define T 555
#define maxn 123
#define inf 0x3f3f3f3f
struct Edge{
	int from,to,dist;
	Edge(){}
	Edge(int _1,int _2,int _3):from(_1),to(_2),dist(_3){}
};
struct HeapNode{
	int d,u;
	HeapNode(){}
	HeapNode(int _1,int _2):d(_1),u(_2){}
	bool operator<(const HeapNode& rhs)const{
		return d>rhs.d;
	}
};
struct Dijkstra{
	int n,m;
	vector<Edge> edges;
	vector<int> G[maxn];
	bool done[maxn];
	int d[maxn];
	int p[maxn];
	void init(int n){
		this->n = n;
		for(int i=0;i<n;++i)G[i].clear();
		edges.clear();
	}
	void AddEdge(int from,int to,int dist){
		edges.push_back(Edge(from,to,dist));
		m = edges.size();
		G[from].push_back(m-1);
	}
	void dijkstra(int s){
		priority_queue<HeapNode> Q;
		for(int i=0;i<n;++i)d[i] = inf;
		d[s] = 0;
		memset(done,0,sizeof(done));
		Q.push(HeapNode(0,s));
		while(!Q.empty()){
			HeapNode x = Q.top();Q.pop();
			int u = x.u;
			if(done[u])continue;
			done[u] = true;
			for(int i=0;i<G[u].size();++i){
				Edge& e = edges[G[u][i]];
				if(d[e.to]>d[u]+e.dist){
					d[e.to] = d[u] + e.dist;
					p[e.to] = G[u][i];
					Q.push(HeapNode(d[e.to],e.to));
				}
			}
		}
	}
};