Dijkstra模板 dj斯特拉

图论里非常常用的dijkstra，自己加了个路径查找，做个模板吧：

int maxn = ;
struct Edge {
    int from,to,dist;
    Edge(int u, int v, int d):from(u),to(v),dist(d)  {}
};
struct HeapNode {
    int d,u;
    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];     //最短路中的上一条弧
    vector<int> path;
    void init(int n) {
        this->n = n;
        for (int i = ; i < n; i++) G[i].clear();
        edges.clear();
        path.clear();
    }

    void addEdge(int from, int to, int dist) {
        edges.push_back(Edge(from,to,dist));
        m = edges.size();
        G[from].push_back(m-);
    }

    void dijkstra(int s) {    //从s点开始
        priority_queue<HeapNode> Q;
        for (int i = ; i < n; i++) d[i] = INF;
        d[s] = ;
        memset(done,,sizeof(done));
        Q.push((HeapNode) {
            ,s
        });
        while (!Q.empty()) {
            HeapNode x = Q.top();
            Q.pop();
            int u = x.u;
            if (done[u]) continue;
            done[u] = true;
            for (int i = ; 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
                    });
                }
            }
        }
    }
    void findpath(int x,int end) {
        path.clear();
        path.push_back(x);
        findd(x,end);
    }
    void findd(int x,int end) {
        if(x==end)
            return;
        else {
            path.push_back(this->edges[this->p[x]].from);
            findd(this->edges[this->p[x]].from,end);
        }
    }
};