刘汝佳
#include<cstdio> #include<cstring> #include<vector> #include<algorithm> #include<queue> using namespace std; #define INF 1e8 const int maxn = 200+10; int n,m; struct Edge { int from,to,dist; Edge(int f,int t,int d):from(f),to(t),dist(d){} }; struct HeapNode { int d,u; HeapNode(int d,int u):d(d),u(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]; 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); } int dijkstra(int s,int e) { priority_queue<HeapNode> Q; for(int i=0;i<n;i++) d[i]=INF; d[s]=0; Q.push(HeapNode(d[s],s)); memset(done,0,sizeof(done)); 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; Q.push(HeapNode(d[e.to],e.to)); } } } if(d[e] == INF) return -1; return d[e]; } }DJ; int main() { while(scanf("%d%d",&n,&m)==2) { DJ.init(n); for(int i=0;i<m;i++) { int u,v,d; scanf("%d%d%d",&u,&v,&d); DJ.AddEdge(u,v,d); DJ.AddEdge(v,u,d); } int s,e; scanf("%d%d",&s,&e); printf("%d ",DJ.dijkstra(s,e) ); } return 0; }
第一:建图
第二: