BZOJ2743 采花

#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define se second
#define fs first
#define ll long long
#define CLR(x) memset(x,0,sizeof x)
#define MC(x,y) memcpy(x,y,sizeof(x))  
#define SZ(x) ((int)(x).size())
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin();it!=(c).end();it++)
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1 
#define INF 2097152
typedef pair<int,int> P;
const double eps=1e-9;
const int maxn=1000100;
const int mod=1e9+7;

ll read()
{
    ll x=0,f=1;char ch=getchar();
    while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
    while(ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}
    return x*f;
}
//-----------------------------------------------------------------------------

bool cmp(P a,P b)
{
    if(a.se==b.se) return a.fs<b.fs;
    return a.se<b.se;
}

P p[maxn],s[maxn];
int a[maxn],pre[maxn],c[maxn],last[maxn];

map<P,int> ans;

void add(int x,int d)
{
    while(x)
    {
        c[x]+=d;
        x-=(x&-x);
    }
}

int sum(int x)
{
    int cnt=0;
    while(x<maxn)
    {
        cnt+=c[x];
        x+=(x&-x);
    }
    return cnt;
}


int main()
{
    int n,c,m;
    cin>>n>>c>>m;
    for(int i=1;i<=n;i++)
    {
         a[i]=read();
         pre[i]=last[a[i]];
         last[a[i]]=i;
    }
    for(int i=1;i<=m;i++)
    {
        p[i].fs=read();p[i].se=read();
        s[i]=p[i];
    }
    sort(p+1,p+m+1,cmp);
    int r=1;
    for(int i=1;i<=m;i++)
    {
        while(r<=p[i].se)
        {
            add(pre[pre[r]],-1);
            add(pre[r],1);
            r++;
        }
        ans[p[i]]=sum(p[i].fs);
    }
    for(int i=1;i<=m;i++) printf("%d\n",ans[s[i]]);
    return 0;
}