zkw费用流+当前弧优化

 var
o,v:array[..] of boolean;
f,s,d,dis:array[..] of longint;
next,p,c,w:array[-..] of longint;
i,j,k,l,y,t,ss,tt,n,ans,imp,flow:longint;
procedure link(i,j,k,l:longint);
begin
inc(t);
next[t]:=d[i]; d[i]:=t; p[t]:=j; c[t]:=k; w[t]:=l;
next[-t]:=d[j]; d[j]:=-t; p[-t]:=i; w[-t]:=-l;
end;
function dfs(i,flow:longint):longint;
var j,k,l,min:longint;
begin
if i=tt then
begin
inc(ans,dis[i]*flow); exit(flow);
end;
k:=s[i]; j:=p[k]; dfs:=;
o[i]:=true; v[i]:=true;
while k<> do
begin
l:=dis[i]+w[k]-dis[j]; min:=flow;
if c[k]<min then min:=c[k];
if(min>)and(l<f[j])then f[j]:=l;
if(min>)and(l=)and(not o[j])then
begin
l:=dfs(j,min);
inc(dfs,l); dec(flow,l);
dec(c[k],l); inc(c[-k],l);
end;
if flow= then break;
s[i]:=next[s[i]];
k:=s[i]; j:=p[k];
end;
o[i]:=false;
end;
begin
build;
repeat
for i:=ss to tt do s[i]:=d[i];
fillchar(v,sizeof(v),false);
fillchar(f,sizeof(f),);
inc(flow,dfs(ss, shl ));
imp:= shl ;
for i:=ss to tt do
if(not v[i])and(f[i]<imp)then imp:=f[i];
for i:=ss to tt do if not v[i] then inc(dis[i],imp);
until imp= shl ;
writeln(ans);
end.

PASCAL

 #include<bits/stdc++.h>
using namespace std;
const int INF=;
int o[],v[],f[],c[],s[],dis[];
int b[],p[],d[],w[];
int j,k,ss,tt,n,ans,imp,flow,cnt;
void link(int i,int j,int k,int l)
{
cnt++; b[cnt]=c[i]; c[i]=cnt; p[cnt]=j; d[cnt]=k; w[cnt]=l;
cnt++; b[cnt]=c[j]; c[j]=cnt; p[cnt]=i; d[cnt]=; w[cnt]=-l;
}
int dfs(int x,int flow)
{
if(x==tt){ ans+=dis[x]*flow; return flow; }
int ans2=; o[x]=; v[x]=;
for(int i=s[x];i;i=b[i])
{
int j=p[i]; int l=dis[x]+w[i]-dis[j]; int mi=min(flow,d[i]);
if((mi>)and(l<f[j]))f[j]=l;
if((mi>)and(l==)and(!o[j]))
{
l=dfs(j,mi);
ans2+=l; flow-=l; d[i]-=l; d[i^]+=l;
}
if(flow==)break; s[x]=b[s[x]];
}
o[x]=; return ans2;
}
int main()
{
cnt=; build;
while()
{
for(int i=ss;i<=tt;i++)s[i]=c[i];
memset(v,,sizeof(v)); for(int i=ss;i<=tt;i++)f[i]=INF;
flow+=dfs(ss,INF); imp=INF;
for(int i=ss;i<=tt;i++)if((!v[i])and(f[i]<imp))imp=f[i];
if(imp==INF)break;
for(int i=ss;i<=tt;i++)if(!v[i])dis[i]+=imp;
}
printf("%d %d\n",flow,ans);
}

C++

05-11 10:54