[color=red]

program esd;

var

p,f,f1:array[0..1001] of longint;

i,j,k,l,m,n,max:longint;

begin

readln(n);

for i:=1 to n do

read(p[i]);

for i:=1 to n do

begin

f[i]:=1;

for j:=1 to i-1 do

begin

if (p[i]>p[j]) and (f[j]+1>f[i]) then f[i]:=f[j]+1;

end;

end;

for i:=n downto 1 do

begin

f1[i]:=1;

for j:=i+1 to n do

begin

if (p[i]>p[j]) and (f1[j]+1>f1[i]) then f1[i]:=f1[j]+1;

end;

end;

for i:=1 to n do if f[i]+f1[i]>max then max:=f[i]+f1[i];

writeln(n-max+1);

end.

求大牛解释，F，F1 的作用..