[AHOI2013]作业 莫队 树状数组

#include<cmath>
#include<cstdio>
#include<algorithm>
#include<string>
#include<cstring>
#include<iostream>
#define REP(i,a,n)for(int i=a;i<=n;++i)
#define CLR(d,a)memset(d,a,sizeof(d));

using namespace std;

void SetIO(string a){
    string in=a+".in", out=a+".out";
    freopen(in.c_str(),"r",stdin);
    freopen(out.c_str(),"w",stdout);
}

void End(){
    fclose(stdin);
    fclose(stdout);
}

const int maxn=300000+4;

int val[maxn];

int n,m;

struct Queries{
    int l,r,a,b;
    Queries(int l=0,int r=0,int a=0,int b=0):l(l),r(r),a(a),b(b){}
}ask[maxn];

void Read(){
    scanf("%d%d",&n,&m);
    REP(i,1,n)scanf("%d",&val[i]);
    REP(i,1,m){
        int a,b,c,d;
        scanf("%d%d%d%d",&a,&b,&c,&d);
        ask[i]=Queries(a,b,c,d);
    }
}

int block, belong[maxn], A[maxn];

int get_belong(int i){ return (i-1)/block+1; }

bool cmp(int i,int j){
    if(belong[ask[i].l]==belong[ask[j].l]) return ask[i].r<ask[j].r;
    return belong[ask[i].l]<belong[ask[j].l];
}

void Build(){
    block=sqrt(n);
    REP(i,1,n) belong[i]=get_belong(i);
    REP(i,1,m) A[i]=i;
    sort(A+1,A+1+m,cmp);
}

int count1[maxn];

struct BIT{
    int C[2][maxn];

    int lowbit(int t){return t&(-t);}

    void update(int pos,int o,int delta){
        while(pos<=n){
            C[o][pos]+=delta;
            pos+=lowbit(pos);
        }
    }

    int query(int pos,int o){
        int sum=0;
        while(pos>0){
            sum+=C[o][pos];
            pos-=lowbit(pos);
        }
        return sum;
    }
    void Modify(int i,int delta){
        if(i==0) return ;
        update(i,0,delta);
        count1[i]+=delta;
        if(delta<0 && count1[i]==0) update(i,1,delta);
        if(delta>0 && count1[i]==1) update(i,1,delta); 
    }

}Tree;

int ans1[maxn], ans2[maxn];

void Work(){
    int l=1,r=1;
    Tree.Modify(val[1],1);
    REP(i,1,m){
        int cur=A[i];
        int l2=ask[cur].l;
        int r2=ask[cur].r;

  
        if(r<r2) { 
            ++r; 
            while(r<=r2){ Tree.Modify(val[r],1), ++r; }
            --r; 
        } 
        else 
            while(r>r2) { Tree.Modify(val[r],-1), --r; }

        if(l<l2) { 
            while(l<l2){ Tree.Modify(val[l],-1);  ++l;  }
        }
        else {
            --l;
            while(l>=l2) { Tree.Modify(val[l],1), --l; }
            ++l;
        }


        ans1[cur]=Tree.query(ask[cur].b,0)-Tree.query(ask[cur].a-1,0);
        ans2[cur]=Tree.query(ask[cur].b,1)-Tree.query(ask[cur].a-1,1);
    }
}

void Print(){
    REP(i,1,m)
        printf("%d %d
",ans1[i],ans2[i]);
}

int main(){
    SetIO("input");
    Read();
    Build();
    Work();
    Print();
    End();
    return 0;
}
原文地址:https://www.cnblogs.com/guangheli/p/9845064.html