滑动窗口

 1 #include <cstdio>
 2 #include <algorithm>
 3 using namespace std;
 4 const int N = 1e5 + 5;
 5 const int inf = 0x3f3f3f3f;
 6 int n, m;
 7 int q1[N], q2[N], h1 = 1, h2 = 1, t1, t2;
 8 
 9 struct A{
10     int x, y;
11 }a[N];
12 bool cmp(A x, A y){
13     return x.x < y.x;
14 }
15 
16 int main(){
17     int ans = inf;
18     scanf("%d%d", &n, &m);
19     for(int i = 1; i <= n; i++) scanf("%d%d", &a[i].x, &a[i].y);
20     sort(a + 1, a + n + 1, cmp);
21     for(int i = 1, j = 0; i <= n; i++){
22         while(h1 <= t1 && q1[h1] < i) h1++;
23         while(h2 <= t2 && q2[h2] < i) h2++;
24         while(a[q1[h1]].y - a[q2[h2]].y < m && j < n){
25             j++;
26             while(h1 <= t1 && a[q1[t1]].y <= a[j].y) t1--;
27             q1[++t1] = j;
28             while(h2 <= t2 && a[q2[t2]].y >= a[j].y) t2--;
29             q2[++t2] = j; 
30         }
31         if(a[q1[h1]].y - a[q2[h2]].y >= m) ans = min(ans, a[j].x - a[i].x);
32     }
33     printf("%d", ans == inf ? -1 : ans);
34     return 0;    
35 }