Gym - 100625D Destination Unknown 最短路

http://codeforces.com/gym/100625/attachments/download/3213/2013-benelux-algorithm-programming-contest-bapc-13-en.pdf

题意：给你一张无向图，t个可能的目的地，问在这t个点中哪些点的最短路中经过了g和h

思路：这是傻逼题，我直接dijstra用vector< set<int> > 保存路径， 最后再去判断下。。好像这并不是出题者想要的解法，不过时间还可以，300+ms

 #pragma comment(linker, "/STACK:1000000000")
 #include <iostream>
 #include <cstdio>
 #include <fstream>
 #include <algorithm>
 #include <cmath>
 #include <deque>
 #include <vector>
 #include <queue>
 #include <string>
 #include <cstring>
 #include <map>
 #include <stack>
 #include <set>
 #define LL long long
 #define MAXN 100005
 #define INF 0x3f3f3f3f
 #define eps 1e-8
 using namespace std;
 struct Edge
 {
     int from, to, dist;
     Edge(int from, int to, int dist):from(from), to(to), dist(dist){};
 };
 struct HeapNode
 {
     int d, u;
     HeapNode(int d, int u):d(d), u(u){};
     bool operator <(const HeapNode& rhs) const{
         return d > rhs.d;
     }
 };
 vector< set<int> > road[MAXN];
 struct Dijstra
 {
     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 = ; i <= n; i++){
             G[i].clear();
             road[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 - );
     }

     void dijstra(int s){
         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;
                     road[e.to].clear();
                     if(road[u].empty()){
                         set<int> tmp;
                         tmp.clear();
                         tmp.insert(u);
                         road[e.to].push_back(tmp);
                     }
                     else{
                         for(int j = ; j < road[u].size(); j++){
                             road[e.to].push_back(road[u][j]);
                             road[e.to][j].insert(u);
                         }
                     }
                     p[e.to] = G[u][i];
                     Q.push(HeapNode(d[e.to], e.to));
                 }
                 else if(d[e.to] == d[u] + e.dist){
                     int w = road[e.to].size();
                     for(int j = ; j < road[u].size(); j++){
                         road[e.to].push_back(road[u][j]);
                         road[e.to][w + j].insert(u);
                     }
                 }
             }
         }
     }
 };
 int n, m, t, g, h, s;
 Dijstra p;
 vector<int> res;
 int main()
 {
 #ifndef ONLINE_JUDGE
     freopen("in.txt", "r", stdin);
     //freopen("out.txt", "w", stdout);
 #endif // OPEN_FILE
     int T;
     scanf("%d", &T);
     while(T--){
         scanf("%d%d%d", &n, &m, &t);
         scanf("%d%d%d", &s, &g, &h);
         int x, y, z;
         p.init(n);
         for(int i = ; i <= m; i++){
             scanf("%d%d%d", &x, &y, &z);
             p.AddEdge(x, y, z);
             p.AddEdge(y, x, z);
         }
         p.dijstra(s);
         res.clear();
         for(int i = ; i <= t; i++){
             scanf("%d", &x);
             for(int j = ; j < road[x].size(); j++){
                 road[x][j].insert(x);
                 if(road[x][j].find(g) != road[x][j].end() && road[x][j].find(h) != road[x][j].end()){
                     res.push_back(x);
                     break;
                 }
             }
         }
         sort(res.begin(), res.end());
         int w = res.size();
         for(int i = ; i < w; i++){
             printf("%d ", res[i]);
         }
         printf("\n");
     }
 }