HDU5845 Best Division

递归写法，好久不写很容易就gg了...

dp[i]=max(dp[j])+1,并且s[i]XORs[j]<=x 

01字典树优化一下转移。

 1 #include <bits/stdc++.h>
 2 #define ll long long
 3 using namespace std;
 4
 5 const int maxn = 1e5+5;
 6 ll a[maxn], s[maxn], f[maxn];
 7 int X, L;
 8 struct T{
 9     int node[maxn][2];
10     int val[maxn];
11     ll dp[maxn];
12     int tot;
13     void init(){
14         node[1][0] = node[1][1] = val[1] = 0;
15         dp[1] = -1e9;
16         tot = 2;
17     }
18     int newnode(){
19         node[tot][0] = node[tot][1] = val[tot] = 0;
20         dp[tot] = -1e9;
21         return tot++;
22     }
23     ll query(int x, int now = 1, int dep = 30){
24         if(dep == -1)
25             return dp[now];
26         ll ret = -1e9;
27         int tmp = (X>>dep)&1, tt = (x>>dep)&1;
28         if(tmp){
29             if(node[now][tt]) ret = max(ret, dp[ node[now][tt] ]);
30             if( node[now][!((x>>dep)&1)] ) ret = max(ret,  query(x, node[now][!((x>>dep)&1)], dep-1));
31             return ret;
32         }
33         if(node[now][tt])
34             return query(x, node[now][tt], dep-1);
35         return ret;
36     }
37     void add(int x, int d, ll v, int now = 1, int dep = 30){
38         if(dep == -1){
39             val[now] += d;
40             if(d > 0)
41                 dp[now] = max(dp[now], v);
42             else if(dp[now] <= v)
43                 dp[now] = -1e9;
44             return ;
45         }
46         int tmp = (x>>dep)&1;
47         if(node[now][tmp] == 0)
48             node[now][tmp] = newnode();
49         add(x, d, v, node[now][tmp], dep-1);
50         val[now] += d;
51         dp[now] = -1e9;
52         if(node[now][0]&&val[ node[now][0] ]) dp[now] = max(dp[now], dp[ node[now][0] ]);
53         if(node[now][1]&&val[ node[now][1] ]) dp[now] = max(dp[now], dp[ node[now][1] ]);
54     }
55 };
56 T Tree;
57 int main(){
58     ios::sync_with_stdio(false);
59     int T; cin >> T;
60     ll n, p, q;
61     while(T--){
62         cin >> n >> X >> L;
63         cin >> a[1] >> p >> q;
64         s[1] = a[1];
65         for(int i = 2; i <= n; i++)
66             a[i] = (a[i-1]*p+q)%268435456, s[i] = a[i]^s[i-1];
67
68         Tree.init();
69         Tree.add(s[0], 1, f[0]);
70         int i = 1;
71         for( ; i <= n&&i <= L; i++){
72             f[i] = Tree.query(s[i])+1;
73             Tree.add(s[i], 1, f[i]);
74         }
75         for( ; i <= n; i++){
76             Tree.add(s[i-L-1], -1, f[i-L-1]);
77             f[i] = Tree.query(s[i])+1;
78             Tree.add(s[i], 1, f[i]);
79         }
80         cout << max(f[n], 0LL)<< endl;
81     }
82     return 0;
83 }