P1886 滑動視窗

單調佇列經典題目直接上程式碼

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<iostream>
 4 using namespace std;
 5 const int sz = 1000010;
 6 int n, k;
 7 int q[sz], p[sz], a[sz];
 8 void work_min() {
 9     int head = 1, tail = 0;
10     for(int i = 1; i <= n; i++) {
 
11         while(head <= tail && q[tail] >= a[i]) tail--;
12         q[++tail] = a[i];
13         p[tail] = i;
14         while(p[head] <= i-k) head++;
15         if(i >= k) printf("%d ", q[head]);
16     }
17     printf("\n");
18 }
19 void work_max() {
20     int head = 1
 
, tail = 0;
21     for(int i = 1; i <= n; i++) {
22         while(head <= tail && a[i] >= q[tail]) tail--;
23         q[++tail] = a[i];
24         p[tail] = i;
25         while(p[head] <= i-k) head++;
26         if(i >= k) printf("%d ", q[head]);
27     }
28     printf("
 
\n");
29 }
30 int main() {
31     scanf("%d%d", &n, &k);
32     for(int i = 1; i <= n; i++)
33         scanf("%d", &a[i]);
34     work_min();
35     work_max();
36     return 0;
37 }