hdu5178 pairs

题目

//打注释的是我的代码，一直超时，别人三行代码顶我一坨，同是尺取法，为什么 我的复杂度就这么高呢？#include <cstdio>#include <queue>#include <stack>#include <algorithm>using namespace std;const int MAX_N = 100010;int arr[MAX_N];int main(){    int n, s;    long long  ans;    int T;    scanf("%d",&T);    while(T--)    {        ans=0;        scanf("%d%d", &n, &s);        for (int i = 0; i < n; i++) scanf("%d", &arr[i]);        int l = 0, r = 0;        stable_sort(arr,arr+n);        int sum = 0;     /*   while (true)        {            if(r==n) break;            while(1)            {                ++r;                if(r==n) break;                if( arr[r]-arr[l]<=s)                    ans++;            }            l++;            r=l;        }*/        int j;        for(int i = 0,j = 0; i < n; i++)        {            while(j + 1 < n && arr[j+1] - arr[i] <= s) j++;            ans += j - i;        }        printf("%lld\n", ans);    }    return 0;}