"BZOJ1305" Dance dancing (Max Stream, split Point, two-part answer)

Test instructions: There are n boys and n Girls at a dance. At the beginning of each song, all the boys and girls fit into the N-dance ballroom. Every boy will not dance with the same girl for two (or more) dance songs. There are some boys and girls who like each other, while others dislike each other (not "one-way Likes"). Each boy is willing to dance with the K-not-like girls at most, and each girl is willing to dance with the K-not-liked boys at most. Given the information that every pair of boys and girls love each other, how many dances can a ball have?

N<=50,k<=30

Idea: The obvious maximum flow problem

Will each male, female is split into two points, one expresses likes, another expresses does not like

Two-point answer

(s,num[i,1]) traffic is mid

(Num[i,4],t) mid

(num[i,1],num[i,2]) (num[i,3],num[i,4]) k

For each other's favorite i,j:

(num[i,1],num[j,4]) 1

Don't like:

(num[i,2],num[j,3]) 1

Judge Maxflow whether =mid*n can

1 varHead,gap,dis:Array[0..10000] ofLongint;2Vet,next,len,fan:Array[1..200000] ofLongint;3Num:Array[1.. -,1..4] ofLongint;4A:Array[1.. -,1.. -] ofChar;5 N,m,i,l,r,mid,last,s,source,src,tot,k1,j:longint;6 ch:string;7 8 procedureAdd (a,b,c:longint);9 beginTen Inc (TOT); Onenext[tot]:=Head[a]; Avet[tot]:=b; -len[tot]:=C; -head[a]:=tot; the Inc (TOT); -next[tot]:=Head[b]; -vet[tot]:=A; -len[tot]:=0; +head[b]:=tot; - End; +  A functionmin (x,y:longint): Longint; at begin -  ifX<y Thenexit (x); - exit (y); - End; -  - functionDFS (u,aug:longint): Longint; in varE,v,t,val,flow:longint; - begin to  ifU=src Thenexit (); +E:=head[u]; val:=s-1; flow:=0; -   whileE<>0  Do the  begin *v:=Vet[e]; $   ifLen[e]>0  ThenPanax Notoginseng   begin -    ifdis[u]=dis[v]+1  Then the    begin +T:=dfs (V,min (len[e],aug-flow)); Alen[e]:=len[e]-T; thelen[fan[e]]:=len[fan[e]]+T; +flow:=flow+T; -     ifDis[source]>=s Thenexit (flow); $     ifAug=flow ThenBreak ; $    End; -val:=min (val,dis[v]); -   End; thee:=Next[e]; -  End;Wuyi  ifflow=0  Then the  begin - Dec (Gap[dis[u]]); Wu   ifgap[dis[u]]=0  Thendis[source]:=s; -dis[u]:=val+1; About Inc (Gap[dis[u]); $  End; - exit (flow); - End; -  A functionMaxflow:longint; + varAns:longint; the begin -Fillchar (Gap,sizeof (GAP),0); $Fillchar (dis,sizeof (DIS),0); thegap[0]:=s; ans:=0; the   whileDis[source]<s Doans:=ans+DFS (source,maxlongint); the exit (ans); the End; -  in procedurebuild; the varI,j:longint; the begin AboutFillchar (Head,sizeof (head),0); thetot:=0; the   fori:=1  toN Do the  begin +Add (Num[i,1],num[i,2],k1); -Add (Num[i,3],num[i,4],k1); the  End;Bayi   fori:=1  toN Do the  begin theAdd (Source,num[i,1],mid); -Add (Num[i,4],src,mid); -  End; the   fori:=1  toN Do the    forj:=1  toN Do the    ifa[i,j]='Y'  ThenAdd (Num[i,1],num[j,4],1) the     ElseAdd (Num[i,2],num[j,3],1); - End; the  the begin theAssign (input,'bzoj1305.in'); Reset (input);94Assign (output,'Bzoj1305.out'); Rewrite (output); the readln (N,K1); the   fori:=1  toN Do the  begin98 READLN (CH); About    forj:=1  toN Doa[i,j]:=Ch[j]; -  End;101   fori:=1  to 200000  Do102   ifIMoD 2=1  Thenfan[i]:=i+1103    Elsefan[i]:=i-1;104   fori:=1  toN Do the    forj:=1  to 4  Do106   begin107Inc (s); num[i,j]:=s;108   End;109source:=s+1; src:=s+2; s:=s+2; thel:=0; R:=n; last:=0;111   whileL<=r Do the  begin113mid:= (l+r) >>1; the build; the   ifMaxflow>=mid*n Then beginLast:=mid; L:=mid+1;End the    Elser:=mid-1;117  End;118 Writeln (last);119 close (input); - close (output);121 End.

"BZOJ1305" Dance dancing (Max Stream, split Point, two-part answer)