codeforces 652D Nested Segments 离散化+树状数组

#include<cstdio>
#include<cstring>
#include<queue>
#include<cstdlib>
#include<algorithm>
#include<vector>
#include<cmath>
using namespace std;
typedef long long LL;
const int N=2e5+5;
const int INF=0x3f3f3f3f;
int a[N<<1],n,d;
struct pair{
  int l,r,id;
  bool operator<(const pair &e)const{
     return r<e.r;
  }
}p[N];
int c[N<<1];
void change(int x){
   for(int i=x;i<=d;i+=i&(-i))
     ++c[i];
}
int query(int x){
  int ans=0;
  for(int i=x;i>0;i-=i&(-i))
    ans+=c[i];
  return ans;
}
int res[N];
int main(){ 
    scanf("%d",&n);
    int tot=0;
    for(int i=1;i<=n;++i){
       scanf("%d%d",&p[i].l,&p[i].r),p[i].id=i;
       a[++tot]=p[i].l;
       a[++tot]=p[i].r;
    }
    sort(a+1,a+1+tot);
    d=1;
    for(int i=2;i<=tot;++i)
      if(a[i]!=a[i-1])a[++d]=a[i];
    sort(p+1,p+1+n);
    for(int i=1;i<=n;++i){
      int r=lower_bound(a+1,a+1+d,p[i].r)-a;
      int l=lower_bound(a+1,a+1+d,p[i].l)-a;
      res[p[i].id]=query(r)-query(l-1);
      change(l);
    }
    for(int i=1;i<=n;++i)
     printf("%d\n",res[i]); 
    return 0;
}