http://acm.cs.ecnu.edu.cn/problem.php?problemid=1468
解题报告：http://www.cnblogs.com/blackcruiser/articles/1997097.html
View Code
1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<algorithm> 5 #include<cmath> 6 #include<queue> 7 #include<stack> 8 #include<string> 9 #include<vector> 10 #include<cstdlib> 11 #include<map> 12 #include<set> 13 using namespace std; 14 #define CL(x,v) memset(x,v,sizeof(x)); 15 #define R(i,st,en) for(int i=st;i<en;++i) 16 #define LL long long 17 #define inf 0x3f3f3f3f 18 19 const int maxn = 101; 20 const int maxm = 1000; 21 int n,m,st,en; 22 struct edge 23 { 24 int v,c,t; 25 edge(){} 26 edge(int v, int c, int t):v(v), c(c), t(t){} 27 }; 28 vector <edge> adj[maxn]; 29 int dis[maxn][maxn * 100 + 1]; 30 bool vis[maxn][maxn * 100 + 1]; 31 int minc[maxn],MAX_C; 32 struct node 33 { 34 int u,c,t; 35 bool operator < (const node & oth) const 36 { 37 return t > oth.t; 38 } 39 node(){} 40 node(int u, int c, int t):u(u), c(c), t(t){} 41 }; 42 int dij() 43 { 44 priority_queue <node> q; 45 dis[st][0] = 0; 46 q.push(node(st, 0, 0)); 47 while (!q.empty()) 48 { 49 node cur = q.top(); 50 q.pop(); 51 if(vis[cur.u][cur.c]) continue; 52 vis[cur.u][cur.c] = 1; 53 if(minc[cur.u] < cur.c) continue; 54 minc[cur.u] = cur.c; 55 for (int i = 0; i < adj[cur.u].size(); ++i) 56 { 57 node nt; 58 nt.u = adj[cur.u][i].v; 59 nt.t = cur.t + adj[cur.u][i].t; 60 nt.c = cur.c + adj[cur.u][i].c; 61 if (nt.c <= MAX_C && nt.t < dis[nt.u][nt.c]) 62 { 63 dis[nt.u][nt.c] = nt.t; 64 q.push(nt); 65 } 66 } 67 } 68 int tmp = 0, min_t = inf; 69 for (int i = 0; i<= MAX_C; ++i) 70 if (dis[en][i] < inf && min_t > dis[en][i]) 71 { 72 tmp++; 73 min_t = dis[en][i]; 74 } 75 return tmp; 76 } 77 void init() 78 { 79 memset(vis, 0, sizeof(vis)); 80 memset(dis, 0x3f, sizeof(dis)); 81 memset(minc, 0x3f, sizeof(minc)); 82 MAX_C = (n - 1) * 100; 83 memset(adj, 0, sizeof(adj)); 84 } 85 int main() 86 { 87 while(~scanf("%d%d%d%d", &n, &m, &st, &en)) 88 { 89 init(); 90 for (int i = 0; i < m; ++i) 91 { 92 int u, v, c, t; 93 scanf("%d%d%d%d", &u, &v, &c, &t); 94 adj[u].push_back(edge(v, c, t)); 95 adj[v].push_back(edge(u, c, t)); 96 } 97 int ans = dij(); 98 printf("%d\n",ans); 99 } 100 return 0; 101 }