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| #include<queue> #include<vector> #include<cstdio> #include<cstring> #include<iostream> #include<algorithm> using namespace std;
typedef pair<int,int> pii; const int N=1e3+10,M=2e3+10,INF=0x3f3f3f3f; const int NP=N+M,NE=3*M+N; #define ci const int & inline int Read(int &r){ int b=1,c=getchar();r=0; while(c<'0' || '9'<c) b=c=='-'? -1:b,c=getchar(); while('0'<=c && c<='9') r=(r<<1)+(r<<3)+(c^'0'),c=getchar(); return r*=b; }
struct EDGE{ int u,v,tov,tou; void Input(){Read(u),Read(v),Read(tov),Read(tou);} }edg[M]; struct FLOWGRAPH{ int head[NP],to[NE<<1],nxt[NE<<1],cap[NE<<1],ncnt; void Init(ci n){ for(int i=0;i<=n;i++) head[i]=0; ncnt=1; } void AddEdge(ci u,ci v,ci ca){ int p=++ncnt,q=++ncnt; to[p]=v,nxt[p]=head[u],head[u]=p,cap[p]=ca; to[q]=u,nxt[q]=head[v],head[v]=q,cap[q]=0; } inline int operator [](ci u){return head[u];} }Fl; struct GRAPH{ int head[N],to[M],nxt[M],id[M],ncnt; void AddEdge(ci u,ci v,ci i){ int p=++ncnt; to[p]=v,nxt[p]=head[u],head[u]=p; id[p]=i; } inline int& operator [](ci u){return head[u];} }Gr; struct QUEUE{ int ary[NP],ql,qr; inline void clear(){ql=1,qr=0;} inline void push(ci x){ary[++qr]=x;} inline void pop(){ql++;} inline bool empty(){return ql>qr;} inline int front(){return ary[ql];} }que;
int n,m,S,T,nans,deg[N],head[NP],dis[NP],tp[N],ans[M];
int Aug(ci u,ci in){ if(u==T) return in; int out=0; for(int &it=head[u];it;it=Fl.nxt[it]){ int v=Fl.to[it]; if(Fl.cap[it]<=0 || dis[v]!=dis[u]+1) continue; int tov=Aug(v,min(in-out,Fl.cap[it])); Fl.cap[it]-=tov,Fl.cap[it^1]+=tov; out+=tov; if(out==in) break; } return out; } bool BFS(){ for(int i=1;i<=T;i++) head[i]=Fl[i],dis[i]=-1; que.clear(); dis[S]=0,que.push(S); while(!que.empty()){ int u=que.front();que.pop(); for(int it=head[u];it;it=Fl.nxt[it]){ int v=Fl.to[it]; if((~dis[v]) || Fl.cap[it]<=0) continue; dis[v]=dis[u]+1; if(v==T) return true; que.push(v); } } return false; } bool Check(ci mid){ Fl.Init(T); int ept=0; for(int i=1;i<=n;i++) Fl.AddEdge(i,T,deg[i]/2),ept+=deg[i]/2; for(int i=1;i<=m;i++){ Fl.AddEdge(S,n+i,1); if(edg[i].tov<=mid) Fl.AddEdge(n+i,edg[i].v,1); if(edg[i].tou<=mid) Fl.AddEdge(n+i,edg[i].u,1); } int out=0; while(BFS()) out+=Aug(S,INF); return out==ept; } void DFS(ci u,ci las){ while(Gr[u]){ int it=Gr[u];Gr[u]=Gr.nxt[it]; int v=Gr.to[it]; DFS(v,Gr.id[it]); } if(las) ans[++nans]=las; } int main(){ int lef=0,rig=0; Read(n),Read(m),S=n+m+1,T=S+1; for(int i=1;i<=m;i++){ edg[i].Input(); rig=max(rig,max(edg[i].tou,edg[i].tov)); lef=max(lef,min(edg[i].tou,edg[i].tov)); deg[edg[i].u]++,deg[edg[i].v]++; } for(int i=1;i<=n;i++) if(deg[i]&1){ printf("NIE\n"); return 0; } while(lef+1<rig){ int mid=(lef+rig)>>1; if(Check(mid)) rig=mid; else lef=mid; } int ans; if(!Check(lef)) ans=rig,Check(rig); else ans=lef; printf("%d\n",ans); for(int i=1;i<=m;i++) for(int it=Fl[i+n];it;it=Fl.nxt[it]){ if((it&1) || Fl.cap[it]>0) continue; int v=Fl.to[it]; if(v==edg[i].v) Gr.AddEdge(edg[i].u,edg[i].v,i); else Gr.AddEdge(edg[i].v,edg[i].u,i); } DFS(1,0); for(int i=m;i>=1;i--) printf("%d%c",::ans[i],i==1? '\n':' '); return 0; }
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