BZOJ 3262: 陌上花开 (cdq分治，三维偏序）

#include <iostream>
#include <stdio.h>
#include <algorithm>
using namespace std;

const int maxn=1e5+10;
const int maxk=2e5+10;

int n,k;

struct Triple {
    int a,b,c,cnt,ans;
}a[maxn],A[maxn];

bool cmp(const Triple &a,const Triple &b) {
    if (a.a!=b.a) {
        return a.a<b.a;
    }
    else if (a.b!=b.b) {
        return a.b<b.b;
    }
    return a.c<b.c;
}

struct BitIndexTree {
    int a[maxk];

    int lowbit(const int x) {
        return x&(-x);
    }

    void Update(const int x,const int delta) {
        for (int i=x;i<=k;i+=lowbit(i)) {
            a[i]+=delta;
        }
    }

    void Clean(const int x) {
        for (int i=x;i<=k;i+=lowbit(i)) {
            if (a[i]) {
                a[i]=0;
            }
            else {
                break;
            }
        }
    }

    int Query(const int x) {
        int ans=0;
        for (int i=x;i>0;i-=lowbit(i)) {
            ans+=a[i];
        }
        return ans;
    }
}bit;   

void CDQ(Triple *l,Triple *r)
{
    if (l==r) {
        l->ans+=l->cnt-1;
        return ;
    }
    Triple *mid=l+(r-l)/2;
    CDQ(l,mid);
    CDQ(mid+1,r);

    static Triple tmp[maxn];
    for (Triple *p=tmp,*p1=l,*p2=mid+1;p<=tmp+(r-l);p++) {
        if ((p1<=mid&&p1->b<=p2->b)||p2>r) {
            *p=*p1++;
            bit.Update(p->c,p->cnt);
        }
        else {
            *p=*p2++;
            p->ans+=bit.Query(p->c);
        }
    }
    for (Triple *p=tmp,*q=l;q<=r;p++,q++) {
        bit.Clean(p->c);
        *q=*p;
    }
}

template <typename T>
inline void read(T &x)
{
    int f=1;
    x=0;
    register char ch;
    ch=getchar();
    while (ch>'9'||ch<'0') {
        if (ch=='-') {
            f=-f;
        }
        ch=getchar();
    }
    while (ch>='0'&&ch<='9') {
        x=x*10+ch-'0';
        ch=getchar();
    }
    x*=f;
}

inline void write(int x)
{
    if (x<0) {
        putchar('-');
    }
    if (x>9) {
        write(x/10);
    }
    putchar(x%10+'0');
}

int main()
{
    scanf("%d%d",&n,&k);
    for (int i=0;i<n;i++) {
        read(a[i].a),read(a[i].b),read(a[i].c);
        // scanf("%d%d%d",&a[i].a,&a[i].b,&a[i].c);
        a[i].cnt=1;
    }
    sort(a,a+n,cmp);
    int cnt=0;
    for (int i=0;i<n;i++) {
        if (i==0||!(a[i].a==a[i-1].a&&a[i].b==a[i-1].b&&a[i].c==a[i-1].c)) {
            A[cnt++]=a[i];
        }
        else {
            A[cnt-1].cnt+=1;
        }
    }
    CDQ(A,A+cnt-1);
    static int ans[maxn];
    for (int i=0;i<cnt;i++) {
        ans[A[i].ans]+=A[i].cnt;
    }
    for (int i=0;i<n;i++) {
        write(ans[i]);
        putchar('\n');
        // printf("%d\n",ans[i]);
    }
    return 0;
}