poj2352

线段树

#include<iostream>
#define maxn 45000
using namespace std;

int cnt[maxn]={0},s[maxn]={0};
int n;

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

int getsum(int x)
{
  int sum=0;
  while(x>0)
  {
    sum+=s[x];
    x-=lowbit(x);
  }
  return sum;
}

void update(int x)
{
  while(x<=maxn)
  {
    s[x]++;x+=lowbit(x);
  }
}

int main()
{
  while(scanf("%d",&n)!=EOF)
  {
    int i,x,y;
    for(i=0;i<n;i++)
    {
      scanf("%d%d",&x,&y);
      cnt[getsum(x+1)]++;
      update(x+1);
    }
    for(i=0;i<n;i++)
      printf("%d\n",cnt[i]);
  }
  return 0;
}