NOI2010超级钢琴 2

  1 const maxn=600000+10;inf=maxlongint;
  2 type node=record
  3      x,y,z:longint;
  4      end;
  5 var s,t:array[0..21,0..maxn] of longint;
  6     a,b:array[0..maxn] of longint;
  7     i,j,n,m,x,y,k,l,r,tmp:longint;
  8     ans:int64;
  9     c:array[0..2*maxn] of node;
 10     w:node;
 11   function max(x,y:longint):longint;
 12    begin
 13    if x>y then exit(x) else exit(y);
 14    end;
 15 
 16   procedure modify(x,y,z:longint);
 17    var k,i:longint;
 18    begin
 19    c[0].x:=x;c[0].y:=y;c[0].z:=z;
 20    i:=1;k:=2;
 21    while k<=m do
 22     begin
 23       if (k<m) and (c[k+1].x>c[k].x) then inc(k);
 24       if c[0].x<c[k].x then begin c[i]:=c[k];i:=k;k:=k<<1;end
 25       else k:=m+1;
 26     end;
 27    c[i]:=c[0];
 28    end;
 29  procedure insert(x,y,z:longint);
 30    var k,i:longint;
 31    begin
 32    inc(m);c[0].x:=x;c[0].y:=y;c[0].z:=z;
 33    i:=m;k:=i>>1;
 34    while k>=1 do
 35      begin
 36       if c[0].x>c[k].x then begin c[i]:=c[k];i:=k;k:=i>>1;end
 37       else k:=0;
 38      end;
 39    c[i]:=c[0];
 40    end;
 41 procedure sort(l,r:longint);
 42  var i,j,m,temp:longint;
 43  begin
 44  i:=l;j:=r;x:=a[(i+j)>>1];
 45  repeat
 46   while b[a[i]]<b[x] do inc(i);
 47   while b[a[j]]>b[x] do dec(j);
 48   if i<=j then
 49    begin
 50    y:=a[i];a[i]:=a[j];a[j]:=y;
 51    inc(i);dec(j);
 52    end;
 53  until i>j;
 54  if i<r then sort(i,r);
 55  if j>l then sort(l,j);
 56  end;
 57 procedure build(h,l,r:longint);
 58  var i,p,mid:longint;
 59  begin
 60  mid:=(l+r)>>1;p:=0;
 61  for i:=l to r do
 62   if t[h,i]<=mid then
 63    begin
 64     t[h+1,l+p]:=t[h,i];
 65     inc(p);
 66     s[h,i]:=p;
 67    end
 68   else
 69    begin
 70     t[h+1,mid+1+i-p-l]:=t[h,i];
 71     s[h,i]:=p;
 72    end;
 73  if l=r then exit;
 74  build(h+1,l,mid);
 75  build(h+1,mid+1,r);
 76  end;
 77 function find(h,l,r,x,y,k:longint):longint;
 78  var ll,rr,mid:longint;
 79  begin
 80  if l=r then exit(t[h,l]);
 81  mid:=(l+r)>>1;
 82  if l=x then ll:=0 else ll:=s[h,x-1];rr:=s[h,y]-ll;
 83  if rr>=k then exit(find(h+1,l,mid,l+ll,l+rr+ll-1,k))
 84  else exit(find(h+1,mid+1,r,mid+1+x-l-ll,mid+1+y-l-rr-ll,k-rr));
 85  end;
 86 procedure init;
 87   begin
 88     readln(n,k,l,r);inc(n);
 89     for i:=2 to n do begin readln(x);b[i]:=b[i-1]+x;end;
 90     for i:=1 to n do a[i]:=i;
 91     sort(1,n);
 92   end;
 93 procedure main;
 94    begin
 95    for i:=1 to n do t[0,a[i]]:=i;
 96    build(0,1,n);//writeln(n);
 97    for i:=l+1 to n do
 98      begin
 99       tmp:=b[a[find(0,1,n,max(i-r,1),i-l,1)]];
100     //  writeln(tmp);
101       insert(b[i]-tmp,i,1);
102      end;
103    ans:=0;
104    for i:=1 to k do
105      begin
106       w:=c[1]; // writeln(w.x);
107       inc(ans,w.x);
108       if (w.z>=r-l+1) or ((w.y<r+1) and (w.z>w.y-l-1)) then modify(-inf,inf,inf)
109       else
110        begin
111         tmp:=b[w.y]-b[a[find(0,1,n,max(w.y-r,1),w.y-l,w.z+1)]];
112         modify(tmp,w.y,w.z+1);
113        end;
114      end;
115    writeln(ans);
116    end;
117 begin
118  assign(input,‘input.txt‘);assign(output,‘output.txt‘);
119  reset(input);rewrite(output);
120  init;
121  main;
122  close(input);close(output);
123 end.