【单调队列】滑动窗口

 P1886 滑动窗口

单调队列经典题目直接上代码

#include<cstdio>
#include<cstring>
#include<iostream>
using namespace std;
const int sz = 1000010;
int n, k;
int q[sz], p[sz], a[sz];
void work_min() {
    int head = 1, tail = 0;
    for(int i = 1; i <= n; i++) {
        while(head <= tail && q[tail] >= a[i]) tail--;
        q[++tail] = a[i];
        p[tail] = i;
        while(p[head] <= i-k) head++;
        if(i >= k) printf("%d ", q[head]);
    }
    printf("
");
}
void work_max() {
    int head = 1, tail = 0;
    for(int i = 1; i <= n; i++) {
        while(head <= tail && a[i] >= q[tail]) tail--;
        q[++tail] = a[i];
        p[tail] = i;
        while(p[head] <= i-k) head++;
        if(i >= k) printf("%d ", q[head]);
    }
    printf("
");
}
int main() {
    scanf("%d%d", &n, &k);
    for(int i = 1; i <= n; i++)
        scanf("%d", &a[i]);
    work_min();
    work_max();
    return 0;
}