namespace Dijkstra     //针对正权图（邻接表） {      typedef int T; //权类型，须指定      const int maxn = 1000; //点的最大数，须指定      typedef pair<T, int> Ti;     //T权类型，int顶点号      typedef vector<Ti>::iterator iter;       vector<Ti> w[maxn];     //图，须输入       T d[maxn];     //点的最小权，输出用      //int p[maxn];       //路径，输出用      void dijkstra( int s )     //源点s       {            priority_queue< Ti, vector<Ti>, greater<Ti> > q;            memset( d, 127, sizeof(d) );            d[s] = 0;            q.push( Ti(0, s) );           while (!q.empty())            {                int u = q.top().second;                 T du = q.top().first;                 q.pop();                if (d[u] != du)                     continue;                for (iter it = w[u].begin(); it != w[u].end(); ++it)                 {                     int v = it->second;                      T dv = du + it->first;                     if (d[v] > dv)                      {                           d[v] = dv;                          //p[v] = u;                           q.push( Ti(dv, v) );                      }                 }            }       } };