hdu3507 Print Article（斜率优化入门）（pascal）

 1 program rrr(input,output);
 2 var
 3   n,m,i,h,t:longint;
 4   q:array[0..500050]of longint;
 5   f,s:array[0..500050]of int64;
 6 function up(j,k:int64):int64;
 7 begin
 8    exit(f[j]-f[k]+sqr(s[j])-sqr(s[k]));
 9 end;
10 function down(j,k:int64):int64;
11 begin
12    exit((s[j]-s[k])<<1);
13 end;
14 begin
15    assign(input,‘r.in‘);assign(output,‘r.out‘);reset(input);rewrite(output);
16    while not eof do
17       begin
18          readln(n,m);
19          s[0]:=0;
20          for i:=1 to n do begin readln(s[i]);s[i]:=s[i]+s[i-1]; end;
21          h:=1;t:=1;q[1]:=0;f[0]:=0;
22          for i:=1 to n do
23             begin
24                while (h<t) and (up(q[h+1],q[h])<=s[i]*down(q[h+1],q[h])) do inc(h);
25                f[i]:=f[q[h]]+sqr(s[i]-s[q[h]])+m;
26                while (t>h) and (up(i,q[t])*down(q[t],q[t-1])<=up(q[t],q[t-1])*down(i,q[t])) do dec(t);
27                inc(t);q[t]:=i;
28             end;
29          writeln(f[n]);
30       end;
31    close(input);close(output);
32 end.