POJ 1273 Sap+Dinic Pascal模板

题目: Drainage Ditches

链接: http://poj.org/problem?id=1273

Sap模板:

<pre name="code" class="delphi">Const  Fin = '';  Fout = '';Const  Maxm = 10000;  Maxn = 10000;Var  t, nt, c, p: Array[1..Maxm]Of Longint;  Ind, h: Array[1..Maxn]Of Longint;  hv: Array[0..Maxn]Of Longint;  i, j, k, x: Longint;  n, m, cnt: Longint;  st, ed: Longint;Function Min(i, j: Longint): Longint;Begin  If i < j Then MIn := i Else Min := j;End;Procedure Addedge(i, j, k: Longint);Begin  Inc(cnt);  t[cnt] := j;  c[cnt] := k;  nt[cnt] := Ind[i];  Ind[i] := cnt;  Inc(cnt);  t[cnt] := i;  c[cnt] := 0;  nt[cnt] := Ind[j];  Ind[j] := cnt;  p[cnt] := cnt - 1;  p[cnt - 1] := cnt;End;Function Aug(x, Lim: Longint): Longint;Var  k, l, d, Minh: Longint;Begin  If x = Ed Then Begin  Aug := LIm; Exit;  End;  k := Ind[x];  l := Lim;  MInh := n;  While k <> -1 Do  Begin    If c[k] > 0 Then    Begin      If h[t[k]] = h[x] - 1 Then      Begin        d := Aug(t[k], Min(c[k], L));        Dec(c[k], d);        Inc(c[p[k]], d);        Dec(l, d);        If l = 0 Then Break;        If h[st] > n Then Begin Aug := Lim - l; Exit; End;      End;      If Minh > h[t[k]] Then Minh := h[t[k]];    End;    k := nt[k];  End;  If l = LIm Then  Begin    Dec(hv[h[x]]);    If hv[h[x]] = 0 Then Begin h[st] := n + 1; Aug := LIm - l; Exit; End;    h[x] := Minh + 1;    Inc(hv[h[x]]);  End;  Aug := LIm - l;End;Function Sap(): Longint;Begin  Fillchar(h, Sizeof(h), 0);  Fillchar(hv, Sizeof(hv), 0);  hv[0] := n;  Sap := 0;  While h[st] < n + 1 Do    Sap := Sap + Aug(st, MaxLongint);End;Begin  Assign(Input, Fin);  Assign(Output, Fout);  Reset(Input);  Rewrite(Output);  While Not Eof(Input) Do  Begin    ReadLn(m, n);    If (m = 0) And (n = 0) Then Break;    Fillchar(Ind, Sizeof(Ind), $FF);    cnt := 0;    For i:=1 To m Do    Begin      Read(j, k, x);      Addedge(j, k, x);    End;    st := 1;    ed := n;    WriteLn(Sap);  End;  Close(Output);End.Dinic模板:Const  Fin = '';  Fout = '';Const  Maxm = 10000;  Maxn = 10000;Var  t, nt, c, p: Array[1..Maxm]Of Longint;  Ind, h: Array[1..Maxn]Of Longint;  Vis: Array[1..Maxn]Of Boolean;  q: Array[0..Maxn]Of Longint;  i, j, k, x: Longint;  n, m, cnt: Longint;  st, ed: Longint;Function Min(i, j: Longint): Longint;Begin  If i < j Then MIn := i Else Min := j;End;Procedure Addedge(i, j, k: Longint);Begin  Inc(cnt);  t[cnt] := j;  c[cnt] := k;  nt[cnt] := Ind[i];  Ind[i] := cnt;  Inc(cnt);  t[cnt] := i;  c[cnt] := 0;  nt[cnt] := Ind[j];  Ind[j] := cnt;  p[cnt] := cnt - 1;  p[cnt - 1] := cnt;End;Function BFS(): Boolean;Var  l, r, k, x: Longint;Begin  Fillchar(Vis, Sizeof(Vis), False);  Fillchar(h, Sizeof(h), 0);  l := 0;  r := 0;  q[l] := st;  Vis[st] := True;  While l <= r Do  Begin    x := q[l];    k := Ind[q[l]];    Inc(l);    While k <> -1 Do    Begin      If (c[k] > 0) And (Not Vis[t[k]]) Then      Begin        h[t[k]] := h[x] + 1;        Inc(r);        q[r] := t[k];        Vis[t[k]] := True;      End;      k := nt[k];    End;  End;  If h[ed] = 0 Then BFS := False Else BFS := True;End;Function DFS(x, lim: Longint): Longint;Var  k, l, d: Longint;Begin  If x = ed Then Begin DFS := Lim; Exit; End;  k := Ind[x];  L := Lim;  dFS := 0;  While k <> -1 Do  Begin    If h[t[k]] = h[x] + 1 Then    Begin      d := DFS(t[k], Min(l, c[k]));      Dec(c[k], d);      Inc(c[p[k]], d);      Dec(l, d);      If l = 0 Then Break;    End;    k := nt[k];  End;  DFS := Lim - l;End;Function Dinic(): Longint;Begin  Dinic := 0;  While BFS Do Dinic := Dinic + DFS(st, MaxLongint);End;Begin  Assign(Input, Fin);  Assign(Output, Fout);  Reset(Input);  Rewrite(Output);  While Not Eof(Input) Do  Begin    ReadLn(m, n);    If (m = 0) And (n = 0) Then Break;    Fillchar(Ind, Sizeof(Ind), $FF);    cnt := 0;    For i:=1 To m Do    Begin      Read(j, k, x);      Addedge(j, k, x);    End;    st := 1;    ed := n;    WriteLn(Dinic);  End;  Close(Output);End.