hiho_1081_最短路径1

题目

    最短路模板题目，纯练习手速。

实现

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#include<iostream> #include<string.h> #include<iostream> #include<queue> #include<cmath> #include<unordered_map> #include<unordered_set> #include<string> #include<vector> #include<algorithm> using namespace std; const int inf = 1 << 29; const int kEdgeMax = 20005; const int kNodeMax = 1005; struct Edge{     int to;     int dist;     int next;     Edge(int t=0, int d=0, int n=0) :to(t), dist(d), next(n){}; }; Edge gEdges[kEdgeMax]; int gEdgesIndex; int gHead[kNodeMax]; int gDist[kNodeMax]; bool gVisited[kNodeMax];   struct Cmp{     bool operator()(const Edge& e1, const Edge& e2){         return e1.dist > e2.dist;     } };   void InsertEdge(int u, int v, int d){     int e = gEdgesIndex++;     gEdges[e].to = v;     gEdges[e].dist = d;     gEdges[e].next = gHead[u];     gHead[u] = e; } //dijkstra 算法求最短路 int Dijkstra(int s, int t){     priority_queue<Edge, vector<Edge>, Cmp> pq;     gDist[s] = 0;     Edge e = Edge(s, 0, 0);     pq.push(e);     while (!pq.empty()){         e = pq.top();         pq.pop();         int cur_v = e.to;         if (gVisited[cur_v]){             continue;         }         if (cur_v == t){             break;         }         gVisited[cur_v] = true;         for (int eid = gHead[cur_v]; eid != -1; eid = gEdges[eid].next){             int next_v = gEdges[eid].to;             if (!gVisited[next_v] && gDist[next_v] > gDist[cur_v] + gEdges[eid].dist){                 gDist[next_v] = gDist[cur_v] + gEdges[eid].dist;                 pq.push(Edge(next_v, gDist[next_v], 0));             }         }     }     return gDist[t]; }   void Init(){     memset(gHead, -1, sizeof(gHead));     memset(gVisited, false, sizeof(gVisited));     memset(gDist, 0x7F, sizeof(gDist));     gEdgesIndex = 0; }   int main(){     int n, m, s, t, u, v, d;     Init();     scanf("%d %d %d %d", &n, &m, &s, &t);     for (int i = 0; i < m; i++){         scanf("%d %d %d", &u, &v, &d);         InsertEdge(u, v, d);         InsertEdge(v, u, d);     }     int min_dist = Dijkstra(s, t);     printf("%d\n", min_dist);     return 0; }