Euler's loop of POJ 1637 hybrid Graph

Create an advanced network flow chart!

When I first read this question, I got scared... No ....

Here is the idea ......

Very good analysis.

I have been searching for it for a long time! It's been a long time! Another variable is not initialized. I will go! Let me run the correct example!

CODE:

#include<iostream>#include<string>#include<cmath>#include<algorithm>#define MN 222#define ME 1111#define FF(i,a,b) for( int i=a;i<b;i++ )#define CC(a) memset( a,0,sizeof(a) )template<class T>void inline checkmin( T &a,T b ){ if(a==-1||a>b) a=b; }using namespace std;struct edge{    int u,v,p;}E[ME];bool Impos;int NV,NE,s,t,in[MN],out[MN],tot;int maze[MN][MN],gap[MN],dis[MN],pre[MN],cur[MN];void setG(){  CC(maze);CC(in);CC(out);  scanf( "%d%d",&NV,&NE );  s=0;t=NV+1;Impos=false;tot=0;  FF( i,0,NE )  {   scanf("%d%d%d",&E[i].u,&E[i].v,&E[i].p );   out[E[i].u]++; in[E[i].v]++;     }     FF( i,1,t )     {   if( abs(in[i]-out[i])&1 )    Impos=true;   if( in[i]>out[i] )    maze[i][t]=(in[i]-out[i])/2;   else    maze[s][i]=(out[i]-in[i])/2; } FF( i,1,t )  tot+=maze[s][i]; FF( i,0,NE ) if( E[i].p==0 )  maze[E[i].u][E[i].v]++;}int sap(){  CC(cur),CC(pre),CC(gap),CC(dis);  int u=pre[s]=s,maxflow=0,aug=-1;  gap[0]=t+1;  while( dis[s]<=t ){loop:for( int v=cur[u];v<=t;v++ )if( maze[u][v]&&dis[u]==dis[v]+1 ) {   cur[u]=v; pre[v]=u;  checkmin( aug,maze[u][v] );   u=v;  if( v==t )  {    maxflow+=aug;  for( u=pre[u];v!=s;v=u,u=pre[u] )  {    maze[u][v]-=aug;   maze[v][u]+=aug; }    aug=-1;   }   goto loop;}int mind=t;for( int v=0;v<=t;v++ )if( maze[u][v]&&mind>dis[v] ){ cur[u]=v; mind=dis[v]; } if( --gap[dis[u]]==0 )break; gap[dis[u]=mind+1]++; u=pre[u];      }      return maxflow;}int main(){ int T; scanf( "%d",&T ); while( T-- ) {    setG();    //printf( "tot:%d\n",tot );    if( Impos || tot!=sap() )       printf( "impossible\n" );    else       printf( "possible\n" );  }  return 0;}