OI刚学萌妹 第六个点WA了 为啥啊

#include<bits/stdc++.h>
const int N=50005;
using namespace std;
int n,D;
struct Node
{
	int pos,h;
	friend istream&operator>>(istream &in,Node &x)	
	{
		in>>x.pos>>x.h;
		return in;
	}
//	friend ostream&operator<<(ostream &out,Node &x)
//	{
//		out<<x.pos<<" "<<x.h;
//		return out;
//	} 
	bool operator <(const Node &x) const
	{
		return this->pos<x.pos;
	}
}p[N];
int sign[N];
void SolveLeft()
{
	int q[N]={0}; int head=1,tail=0;
	for(int i=1;i<=n;i++)
	{
		while(head<=tail && p[i].pos-p[q[head]].pos>D)	head++;
		if(p[q[head]].h>=2*p[i].h)	sign[i]++;
		while(head<=tail && p[i].h>=p[q[tail]].h)	tail--;
		q[++tail]=i;
	}
	//for(int i=1;i<=n;i++)	cout<<sign[i]<<" ";
}
void SolveRight()
{
	int q[N]={0}; int head=1,tail=0;
	for(int i=n;i>=1;i--)
	{
		while(head<=tail && p[i].pos-p[q[head]].pos>D)	head++;
		if(p[q[head]].h>=2*p[i].h)	sign[i]++;
		while(head<=tail && p[i].h>=p[q[tail]].h)	tail--;
		q[++tail]=i;
	}
int main()
{
	cin>>n>>D;
	for(int i=1;i<=n;i++)	cin>>p[i];
	sort(p+1,p+n+1);
	SolveLeft(); 
	SolveRight();
	int ans=0;
	for(int i=1;i<=n;i++)	if(sign[i]==2)	ans++;
	cout<<ans<<endl;
	return 0;
}