P1102 A-B 数对

P1102 A-B 数对

#include

//P2421 A-B数对（增强版）
#include
#include
using namespace std;
int a[100001];
int main()
{
	int n,c;
	cin>>n>>c;
	for (int i=0;icin>>a[i];
	}
	long long ans=0;
	for (int i=0;ilong long s1=lower_bound(a,a+n,a[i]+c)-a;
		long long s2=upper_bound(a,a+n,a[i]+c)-a;
		ans=ans+s2-s1;
	}
	cout<endl;
	
}