BZOJ 2821作诗(Poetize) 分块

 1 #include <cstdio>
 2 #include <cstdlib>
 3 #include <cstring>
 4 #include <string>
 5 #include <algorithm>
 6 #include <cmath>
 7 
 8 using namespace std;
 9 
10 #define REP(i, a, b) for (int i = (a), i##_end_ = (b); i <= i##_end_; ++i)
11 const int maxn = 1e5+10;
12 int n, c, m, a[maxn];
13 int bel[maxn], l[maxn], r[maxn];
14 int cnt[350][maxn], s_block, t[maxn], f[350][350];
15 
16 int solve(int x, int y)
17 {
18     int L = bel[x], R = bel[y];
19     if (L == R)
20     {
21         REP(i, x, y) t[a[i]] = 0;
22         int ret = 0;
23         REP(i, x, y) if (t[a[i]] ++) ret += (t[a[i]]&1) ? -1 : 1;
24         return ret;
25     }
26     else
27     {
28         int ret = f[L+1][R-1];
29         REP(i, x, r[L]) t[a[i]] = 0;
30         REP(i, l[R], y) t[a[i]] = 0;
31         REP(i, x, r[L]) if (!t[a[i]]) t[a[i]] = cnt[R-1][a[i]]-cnt[L][a[i]];
32         REP(i, l[R], y) if (!t[a[i]]) t[a[i]] = cnt[R-1][a[i]]-cnt[L][a[i]];
33         REP(i, x, r[L]) if (t[a[i]] ++) ret += (t[a[i]]&1) ? -1 : 1;
34         REP(i, l[R], y) if (t[a[i]] ++) ret += (t[a[i]]&1) ? -1 : 1;
35         return ret;
36     }
37 }
38 
39 int main()
40 {
41     scanf("%d %d %d", &n, &c, &m);
42     REP(i, 1, n) scanf("%d", &a[i]);
43     int block = int(sqrt(n));
44     REP(i, 1, n)
45     {
46         bel[i] = i/block+1, r[bel[i]] = i;
47         if (i == 1 || bel[i] != bel[i-1]) l[bel[i]] = i;
48     }
49     s_block = n/block+1;
50     REP(i, 1, s_block)
51     {
52         REP(j, 1, c) t[j] = 0;
53         REP(j, i, s_block)
54         {
55             f[i][j] = (j == i) ? 0 : f[i][j-1];
56             REP(k, l[j], r[j]) if (t[a[k]] ++) f[i][j] += (t[a[k]]&1) ? -1 : 1;
57         }
58     }
59     REP(i, 1, s_block)
60     {
61         REP(j, 1, c) cnt[i][j] = cnt[i-1][j];
62         REP(j, l[i], r[i]) cnt[i][a[j]] ++;
63     }
64     int x, y, ans = 0;
65     while (m --)
66     {
67         scanf("%d %d", &x, &y);
68         x = (x+ans)%n+1, y = (y+ans)%n+1;
69         if (x > y) swap(x, y);
70         printf("%d\n", ans = solve(x, y));
71     }
72     return 0;
73 }