P1697: [Usaco2007 Feb]Cow Sorting牛排序

 1 const maxn=100001;
 2 var n,i,j,maxx,minx,now,len,cursum,tmin,sum:longint;
 3 p:array[0..maxn] of boolean;
 4 agr,pos:array[0..maxn] of longint;
 5 function min(a,b:longint):longint;
 6 begin
 7   if a>b then exit(b)
 8     else exit(a);
 9 end;
10 begin
11   readln(n);
12   minx:=maxn;
13   for i:=1 to n do
14     begin
15       readln(agr[i]);
16       inc(pos[agr[i]]);
17       minx:=min(minx,agr[i]);
18       maxx:=maxx+agr[i]-min(maxx,agr[i]);
19     end;
20   //writeln(minx,‘ ‘,maxx);
21   for i:=1 to maxx do
22     inc(pos[i],pos[i-1]);
23   fillchar(p,sizeof(p),true);
24   for i:=1 to n do
25     if p[i] then
26       begin
27         now:=i;
28         tmin:=agr[i];
29         len:=0;
30         cursum:=0;
31         while p[now] do
32           begin
33             inc(len);
34             tmin:=min(tmin,agr[now]);
35             inc(cursum,agr[now]);
36             p[now]:=false;
37             now:=pos[agr[now]];
38           end;
39         if len>1 then inc(sum,cursum);
40         if len>2 then inc(sum,min((len-2)*tmin,minx*(len+1)+tmin));
41      end;
42   writeln(sum);
43 end.