记录编号	119827	评测结果	AAAAAAAAAA
题目名称	三元数对	最终得分	100
用户昵称	稠翼	是否通过	通过
代码语言	Pascal	运行时间	0.102 s
提交时间	2014-09-14 15:22:49	内存使用	2.46 MiB

program cogs1260;
var
a,b,c:array[0..50000,0..1]of int64;
l,r,j,i,k,n:longint;
ans:int64;
procedure init;
begin
     assign(input,'three.in');reset(input);
     assign(output,'three.out');rewrite(output);
end;
procedure sort(l,r:longint);
var
   mid:longint;
begin
     if l>=r then exit;
     mid:=(l+r)shr 1;
     sort(l,mid);
     sort(mid+1,r);
     k:=l;i:=l;j:=mid+1;
     while k<=r do
     begin
          if(a[i,0]<a[j,0])and(i<=mid)and(j<=r) then
          begin
               b[k,0]:=a[i,0];
               b[k,1]:=a[i,1];
               inc(c[a[i,1],1],r-j+1);
               inc(k);
               inc(i);
          end
          else if (a[i,0]>=a[j,0])and(i<=mid)and(j<=r) then
          begin
               b[k,0]:=a[j,0];
               b[k,1]:=a[j,1];
               inc(c[a[j,1],0],i-l);
               inc(k);
               inc(j);
          end else
          if i>mid then
          begin
               b[k,0]:=a[j,0];
               b[k,1]:=a[j,1];
               inc(c[a[j,1],0],i-l);
               inc(k);
               inc(j);
          end else
          if j>r then
          begin
               b[k,0]:=a[i,0];
               b[k,1]:=a[i,1];
               inc(k);
               inc(i);
          end;
          end;
     for i:=l to r do
     begin
          a[i,0]:=b[i,0];
          a[i,1]:=b[i,1];
     end;
end;
procedure main;
begin
     readln(n);
     for i:=0 to n-1 do
     begin
          readln(a[i,0]);
          a[i,1]:=i+1;
     end;
     sort(0,n-1);
     for i:=0 to n-1 do inc(ans,c[i,0]*c[i,1]);
     writeln(ans);
end;
begin
     init;
     main;
     close(output);
end.//complete by chouyi20140913