P3371 "template" single source shortest path (weakened version)
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- 56.1 K submit
- topic provider hansbug webmaster Group
- Evaluation method Cloud evaluation
- tags o2 optimization high performance
- difficulty popularity/Enhancement-
- Space-time limit 1000MS/128MB
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The test data for the random data, in the exam may appear in the construction of data let SPFA not pass, if necessary, please go to P4779.
Title Description
Title, given a direction graph, output the shortest path length from a point to all points.
Input output Format input format:
The first line contains three integers n, M, S, respectively, the number of points, the number of forward edges, the number of starting point.
The next M-line contains three integers of fi, Gi, Wi, respectively, indicating the starting point, target point and length of the forward edge of article I.
Output format:
A row that contains n spaces separated by integers, where the I integer indicates the shortest path length from point s to points I (if s=i, the shortest path length is 0, and if from point S cannot reach point I, the shortest path length is 2147483647)
Input and Output sample input sample #: Copy
4 6 11 2 22 3 22 4 11 3 53 4 31 4 4
Output Example # #: Replication
0 2 4 3
Description
Time limit: 1000ms,128m
Data size:
For 20% of data:n<=5,m<=15;
For 40% of data:n<=100,m<=10000;
For 70% of data:n<=1000,m<=100000;
For 100% of data: n<=10000,m<=500000. Ensure that data is random.
#include <bits/stdc++.h>using namespacestd;#defineINF 0x3f3f3f3fusing namespacestd;intN, M;structnode{intto, cost;};structnode2{BOOLFriendoperator<(Node2 N1, Node2 n2) {returnn1.d >n2.d; } intID, D;}; Vector<node>g[200000+Ten];BOOLfinish[200000+Ten];intdis[200000+Ten];voidMyinit () {memset (finish,0,sizeof(finish)); for(inti =0; I <200001; i++) {g[i].clear (); } memset (DIS, INF,sizeof(DIS));}voidDijkstraints) {Priority_queue<node2>Q; Dis[s]=0; Node2 nn1; Nn1.id= S; NN1.D =Dis[s]; Q.push (NN1); while(!Q.empty ()) {Node2 nn2=Q.top (); Q.pop (); intnow =nn2.id; if(Finish[now])Continue; ElseFinish[now] =1; for(inti =0; I < g[now].size (); i++) { if(!finish[g[now][i].to] && g[now][i].cost + Dis[now] <Dis[g[now][i].to]) {Dis[g[now][i].to]= G[now][i].cost +Dis[now]; } Node2 nn3; Nn3.id= G[now][i].to; NN3.D =Dis[g[now][i].to]; Q.push (NN3); } }}intMain () {intI, J, X, Y, C, S, t; while(SCANF ("%d%d%d", &n, &m,&s)! =EOF) {Myinit (); for(i =0; I < m; i++) {scanf ("%d%d%d", &x, &y, &c); Node N1; N1.to= y; N1.cost =C; G[x].push_back (N1); } Dijkstra (s); for(t=1; t<=n;t++){ if(Dis[t] = =inf) cout<<"2147483647"; Elsecout<<Dis[t]; if(t==n) printf ("\ n"); Elseprintf" "); } } return 0;}
Shortest path dijs+ Priority queue Template