bzoj1715[usaco2006 Dec]wormholes Wormhole *

bzoj1715[usaco2006 Dec]wormholes Insect Cave

Test instructions

Determine if a graph has a negative ring. Points ≤500, number of sides ≤3000. (I do not understand the original question, and then read the problem, it is directly said)

Exercises

SPFA If a point has been updated more than n times, then there is a negative ring in this diagram.

Code:

1#include <cstdio>2#include <cstring>3#include <algorithm>4#include <queue>5 #defineInc (I,J,K) for (int i=j;i<=k;i++)6 #defineMAXN 5107 #defineINF 0X3FFFFFFF8 using namespacestd;9 TenInlineintRead () { One     CharCh=getchar ();intf=1, x=0; A      while(ch<'0'|| Ch>'9'){if(ch=='-') f=-1; Ch=GetChar ();} -      while(ch>='0'&&ch<='9') x=x*Ten+ch-'0', ch=GetChar (); -     returnf*x; the } - structe{intT,w,n;} es[maxn* the];intg[maxn],ess; - voidPeintFintTintW) {es[++ess]= (e) {t,w,g[f]}; g[f]=ess;} - intF,N,M,W,D[MAXN],CNT[MAXN];BOOLINQ[MAXN]; queue<int>Q; + BOOLSPFA () { -      while(!q.empty ()) Q.pop (); Inc (I,1, N) d[i]=inf,cnt[i]=inq[i]=0; d[1]=0; inq[1]=1; Q.push (1); +      while(!Q.empty ()) { A         intX=q.front (); Q.pop (); inq[x]=0; at          for(intI=G[X];I;I=ES[I].N)if(d[es[i].t]>d[x]+ES[I].W) { -D[ES[I].T]=D[X]+ES[I].W; cnt[es[i].t]++;if(cnt[es[i].t]>n)return 1; -             if(!inq[es[i].t]) Q.push (es[i].t), inq[es[i].t]=1; -         } -     } -     return 0; in } - intMain () { tof=read (); +      while(f--){ -N=read (); M=read (); W=read (); Memset (G,0,sizeof(g)); ess=0; theInc (I,1, m) {intX=read (), Y=read (), z=read (); PE (x, y, z); PE (Y,X,Z);} *Inc (I,1, W) {intX=read (), Y=read (), Z=read (); PE (x,y,-z);} $         if(SPFA ()) puts ("YES");ElsePuts"NO");Panax Notoginseng     } -     return 0; the}

20160912

bzoj1715[usaco2006 Dec]wormholes Wormhole *