12D-三维线段树

#include<cstdio>
#include<map>
#include<cstring>
#include<algorithm>

using namespace std;

const int maxn = 500010;
const int inf = 1<<30;

struct node
{
    int b,i,l;
    bool operator<(const node &x) const
    {
        if(b==x.b)
        {
            if(i==x.i)
            {
                return l < x.l;
            }
            return i > x.i;
        }
        return b < x.b;
    }
}ji[maxn];

int main()
{
    int n;
    map<int,int> mp;
    map<int,int>::iterator it;
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
        scanf("%d",&ji[i].b);
    for(int i=1;i<=n;i++)
        scanf("%d",&ji[i].i);
    for(int i=1;i<=n;i++)
        scanf("%d",&ji[i].l);
    sort(ji+1,ji+n+1);
    mp[inf] = -inf;
    mp[-inf] = inf;
    int res = 0;
    for(int i=n;i>=1;i--)
    {
        it = mp.upper_bound(ji[i].i);
        if(ji[i].l<it->second)
            res++;
        else if(mp[ji[i].i]<ji[i].l)
        {
            mp[ji[i].i] = ji[i].l;
            for(it = --mp.lower_bound(ji[i].i);it->second<=ji[i].l;)
                mp.erase(it--);
        }
    }
    printf("%d\n",res);
}