POJ Optimal Milking 2012-08-28

Program poj2112;

var n,c,m,mid,s,t:longint;

map,a:array[1..300,1..300]of longint;

cur,dis:array[1..300]of longint;

vh:array[0..300]of longint;

Procedure init;

var i,j,k:longint;

begin

readln(n,c,m);

for i:=1 to n+c do

for j:=1 to n+c do

read(map[i,j]);

s:=n+c+1;t:=n+c+2;

end;

Procedure floyed;

var i,j,k:longint;

begin

for k:=1 to n+c do

for i:=1 to n+c do

for j:=1 to n+c do

if (i<>j)and(i<>k)and(j<>k)and(map[i,k]<>0)and(map[k,j]<>0) then

begin

if (map[i,j]=0)or(map[i,k]+map[k,j]<map[i,j]) then map[i,j]:=map[i,k]+map[k,j];

end;

end;

Function min(a,b:longint):longint;

begin

if a<b then min:=a else min:=b;

end;

Function aug(x,nf:longint):longint;

var i,j,d,l,minh,ins:longint;

begin

if x=t then exit(nf);

l:=nf;

for i:=cur[x] to t do

if (a[x,i]>0)and(dis[x]=dis[i]+1) then

begin

cur[x]:=i;

d:=aug(i,min(l,a[x,i]));

dec(a[x,i],d);

inc(a[i,x],d);

dec(l,d);

if (dis[s]=t)or(l=0) then exit(nf-l);

end;

if nf=l then

begin

minh:=t;

for i:=1 to t do

if (a[x,i]>0)and(dis[i]<minh) then

begin

minh:=dis[i];ins:=i;

end;

cur[x]:=ins;

dec(vh[dis[x]]);

if vh[dis[x]]=0 then dis[s]:=t;

dis[x]:=minh+1;

inc(vh[dis[x]]);

end;

aug:=nf-l;

end;

Function flow:longint;

var i,j,k:longint;

begin

flow:=0;

fillchar(vh,sizeof(vh),0);

vh[0]:=t;

fillchar(dis,sizeof(dis),0);

for i:=1 to t do cur[i]:=1;

fillchar(a,sizeof(a),0);

for i:=1 to n do

for j:=n+1 to n+c do

if (map[i,j]<>0)and(map[i,j]<=mid) then a[i,j]:=1;

for i:=1 to n do a[s,i]:=m;

for i:=n+1 to n+c do a[i,t]:=1;

while dis[s]<t do inc(flow,aug(s,maxlongint));

end;

Procedure main;

var i,j,k,lc,rc,ans:longint;

begin

floyed;

lc:=0;rc:=200000;

ans:=0;

while lc<rc-1 do

begin

mid:=(lc+rc)div 2;

if flow=c then begin rc:=mid;ans:=mid;end

else lc:=mid;

end;

writeln(ans);

end;

Begin

assign(input,'input.in');assign(output,'output.out');

reset(input);rewrite(output);

init;

main;

close(input);close(output);

end.