加一个sort就行了
```c
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<algorithm>
using namespace std;
long long n,d,a[1000001],cnt,l=1,r=2;
int main()
{
cin>>n>>d;
for(int i=1; i<=n; i++)
{
cin>>a[i];
}
sort(a+1,a+1+n);
while(l<n)
{
if(abs(a[l]-a[r])<=d)
{
++cnt;
r++;
}
else
{
++l;
r=l+1;
}
}
cout<<cnt;
return 0;
}
```
by Fast_IO @ 2021-10-01 22:49:40
谢谢
by XPKAAA @ 2021-10-05 17:48:38