cowhome.pas

来自「Magio牛的usaco源代码」· PAS 代码 · 共 31 行

{
PROB:cowhome
LANG:PASCAL
}

program cowhome;
const
  maxn=1000;
  maxt=2000;
var
  dist:array[1..maxn]of longint;
  v1,v2:array[1..maxt]of word;
  l:array[1..maxt]of byte;
  t,n,i,j:word;
begin
  assign(input,'cowhome.in');reset(input);
  assign(output,'cowhome.out');rewrite(output);
  read(t,n);
  for i:=1 to t do
    read(v1[i],v2[i],l[i]);
  for i:=2 to n do
    dist[i]:=999999;
  for i:=2 to n do
    for j:=1 to t do begin
      if dist[v1[j]]+l[j]<dist[v2[j]] then dist[v2[j]]:=dist[v1[j]]+l[j];
      if dist[v2[j]]+l[j]<dist[v1[j]] then dist[v1[j]]:=dist[v2[j]]+l[j];
    end;
  writeln(dist[n]);
  close(input);close(output);
end.