标签：accept lis long body each ace eve his log
| Time Limit: 2000MS | Memory Limit: 65536K | |
| Total Submissions: 54435 | Accepted: 20273 |
While exploring his many farms, Farmer John has discovered a number of amazing wormholes. A wormhole is very peculiar because it is a one-way path that delivers you to its destination at a time that is BEFORE you entered the wormhole! Each of FJ‘s farms comprises N (1 ≤ N ≤ 500) fields conveniently numbered 1..N, M (1 ≤ M ≤ 2500) paths, and W (1 ≤ W ≤ 200) wormholes.
As FJ is an avid time-traveling fan, he wants to do the following: start at some field, travel through some paths and wormholes, and return to the starting field a time before his initial departure. Perhaps he will be able to meet himself :) .
To help FJ find out whether this is possible or not, he will supply you with complete maps to F (1 ≤ F ≤ 5) of his farms. No paths will take longer than 10,000 seconds to travel and no wormhole can bring FJ back in time by more than 10,000 seconds.
2 3 3 1 1 2 2 1 3 4 2 3 1 3 1 3 3 2 1 1 2 3 2 3 4 3 1 8
NO YES
1 #include<stdio.h> 2 #include<string.h> 3 4 #define inf 99999999 5 #define N 6000 6 7 int main() 8 { 9 int i, j, n, m, check, T, h, flag, k; 10 int dis[N], u[N], v[N], w[N]; 11 scanf("%d", &T); 12 while(T--){ 13 flag = 0; 14 scanf("%d%d%d", &n, &m, &h); 15 for(i = 1; i <= 2*m; i += 2){ 16 scanf("%d%d%d", &u[i], &v[i], &w[i]); 17 u[i+1] = v[i]; 18 v[i+1] = u[i]; 19 w[i+1] = w[i]; 20 } 21 for(i = 2*m+1; i <= 2*m+h; i++){ 22 scanf("%d%d%d", &u[i], &v[i], &w[i]); 23 w[i] = -w[i]; 24 } 25 26 for(i = 1; i <= n; i++) 27 dis[i] = inf; 28 dis[1] = 0; 29 for(j = 1; j <= n-1; j++){ 30 check = 1; 31 for(i = 1; i <= 2*m+h; i++){ 32 if(dis[v[i]] > dis[u[i]] + w[i]){ 33 dis[v[i]] = dis[u[i]] + w[i]; 34 check = 0; 35 } 36 } 37 if(check) 38 break; 39 } 40 for(i = 1; i <= 2*m+h; i++) 41 if(dis[v[i]] > dis[u[i]] + w[i]){ 42 flag = 1; 43 break; 44 } 45 if(flag) 46 printf("YES\n"); 47 else 48 printf("NO\n"); 49 } 50 return 0; 51 }
poj 3259 Wormholes 【最短路之负权环的判断】
标签：accept lis long body each ace eve his log
原文地址：http://www.cnblogs.com/didideblog/p/7399065.html
