[BZOJ1264][AHOI2006]基因匹配Match（DP + 树状数组）

 1 #include <cstdio>
 2 #include <cstring>
 3 #include <iostream>
 4 
 5 using namespace std;
 6 
 7 const int MAXN = 200001;
 8 int n, cnt, ans;
 9 int a[MAXN], c[MAXN];
10 int head[MAXN], to[MAXN << 4], next[MAXN << 4];
11 
12 inline int query(int x)
13 {
14     int ret = 0;
15     for(; x; x -= x & -x) ret = max(ret, c[x]);
16     return ret;
17 }
18 
19 inline void update(int x, int d)
20 {
21     for(; x <= n; x += x & -x) c[x] = max(c[x], d);
22 }
23 
24 inline void add(int x, int y)
25 {
26     to[cnt] = y;
27     next[cnt] = head[x];
28     head[x] = cnt++;
29 }
30 
31 int main()
32 {
33     int i, j, x;
34     scanf("%d", &n);
35     n *= 5;
36     memset(head, -1, sizeof(head));
37     for(i = 1; i <= n; i++) scanf("%d", &a[i]);
38     for(i = 1; i <= n; i++) scanf("%d", &x), add(x, i);
39     for(i = 1; i <= n; i++)
40         for(j = head[a[i]]; j != -1; j = next[j])
41         {
42             x = query(to[j] - 1) + 1;
43             update(to[j], x);
44             ans = max(ans, x);
45         }
46     printf("%d", ans);
47     return 0;
48 }