bzoj2743 [HEOI2012]采花

 1 #include<cstdio>
 2 #include<algorithm>
 3 #include<vector>
 4 #define pb push_back
 5 #define mp make_pair
 6 #define fi first
 7 #define sc second
 8 #define lb(x) (x&-x)
 9 #define N 1000010
10 #define P 1000000007
11 using namespace std;
12 int n,c[N],C,m,i,a,j,b,ans[N],e[N];
13 int pos[N],next[N];
14 vector<int> vec[N];
15 vector<pair<int,int> > q[N],vec2[N];
16 void cc(int x,int w)
17 {
18     while (x<=n)
19     {
20         c[x]+=w;
21         x+=lb(x);
22     }
23 }
24 int sum(int x)
25 {
26     int ans=0;
27     while (x)
28     {
29         ans+=c[x];
30         x-=lb(x);
31     }
32     return ans;
33 }
34 int main()
35 {
36     scanf("%d%d%d",&n,&C,&m);
37     for (i=1;i<=n;i++)
38     {
39         scanf("%d",&a);
40         e[i]=a;
41         vec[pos[a]].pb(i);
42         next[pos[a]]=i;
43         pos[a]=i;
44     }
45     for (i=1;i<=C;i++)
46     pos[i]=0;
47     for (i=1;i<=n;i++)
48     {
49         vec2[pos[e[i]]].pb(mp(i,next[i]));
50         pos[e[i]]=i;
51     }
52     
53     for (i=1;i<=m;i++)
54     {
55         scanf("%d%d",&a,&b);
56         q[a].pb(mp(b,i));
57     }
58     for (i=0;i<=n;i++)
59     {
60         if (i)
61         for (j=0;j<q[i].size();j++)
62         ans[q[i][j].sc]=sum(q[i][j].fi)-sum(i-1);
63         for (j=0;j<vec[i].size();j++) cc(vec[i][j],1);
64     }
65     for (i=1;i<=n;i++) c[i]=0;
66     for (i=0;i<vec2[0].size();i++) cc(vec2[0][i].fi,-1);
67     
68     for (i=0;i<=n;i++)
69     {
70         if (i)
71         for (j=0;j<q[i].size();j++)
72         ans[q[i][j].sc]-=sum(q[i][j].fi)-sum(i-1);
73         for (j=0;j<vec2[i].size();j++) 
74         {
75             cc(vec2[i][j].fi,2);
76             if (vec2[i][j].sc)
77             cc(vec2[i][j].sc,-1);
78         }
79     }
80     for (i=1;i<=m;i++)
81     printf("%d\n",ans[i]);
82 }