【BZOJ3939】Cow Hopscotch（动态开点线段树）

 1 const mo=1000000007;
 2 var t:array[0..7000000]of record
 3                            l,r,s:longint;
 4                           end;
 5 
 6     sum,a,dp:array[0..800,0..800]of longint;
 7     root:array[0..1000000]of longint;
 8     f:array[0..800]of longint;
 9     n,m,i,j,s1,s2,cnt,k:longint;
10 
11 procedure pushup(x:longint);
12 var l,r:longint;
13 begin
14  l:=t[x].l; r:=t[x].r;
15  t[x].s:=(t[l].s+t[r].s) mod mo;
16 end;
17 
18 procedure update(var p:longint;l,r,x,v:longint);
19 var mid:longint;
20 begin
21  if p=0 then
22  begin
23   inc(cnt); p:=cnt;
24  end;
25  if l=r then
26  begin
27   t[p].s:=(t[p].s+v) mod mo; exit;
28  end;
29  mid:=(l+r)>>1;
30  if x<=mid then update(t[p].l,l,mid,x,v)
31   else update(t[p].r,mid+1,r,x,v);
32  pushup(p);
33 end;
34 
35 function query(p,l,r,x,y:longint):longint;
36 var mid:longint;
37 begin
38 
39  if (p=0)or(x>y) then exit(0);
40  if (x<=l)and(y>=r) then exit(t[p].s);
41  mid:=(l+r)>>1;
42  query:=0;
43  if x<=mid then query:=(query+query(t[p].l,l,mid,x,y)) mod mo;
44  if y>mid then query:=(query+query(t[p].r,mid+1,r,x,y)) mod mo;
45 end;
46 
47 
48 begin
49 // assign(input,‘bzoj3939.in‘); reset(input);
50 // assign(output,‘bzoj3939.out‘); rewrite(output);
51  readln(n,m,k);
52  for i:=1 to n do
53   for j:=1 to m do read(a[i,j]);
54 
55  dp[1,1]:=1;
56  for i:=1 to m do sum[1,i]:=1;
57  update(root[a[1,1]],1,m,1,1);
58 
59  for i:=2 to n do
60  begin
61   for j:=m downto 1 do
62   begin
63    s1:=sum[i-1,j-1];
64    s2:=query(root[a[i,j]],1,m,1,j-1);
65    dp[i,j]:=((s1-s2) mod mo+mo) mod mo;
66    update(root[a[i,j]],1,m,j,dp[i,j]);
67   end;
68   for j:=1 to m do
69   begin
70    f[j]:=(f[j-1]+dp[i,j]) mod mo;
71    sum[i,j]:=(sum[i-1,j]+f[j]) mod mo;
72   end;
73  end;
74   writeln(dp[n,m]);
75  {for i:=1 to n do
76  begin
77   for j:=1 to m do write(dp[i,j],‘ ‘);
78   writeln;
79  end; }
80 
81 
82  close(input);
83  close(output);
84 end.