$\Huge要用快读！！！$

$\Huge要用快读！！！$

$\Huge要用快读！！！$

重要的事情说三遍
不用快读：

#include<bits/stdc++.h>
using namespace std;
deque<pair<int, int>> q;
int main()
{
	register int n, k;
	scanf("%d%d", &n, &k);
	for(register int i = 1; i <= n; ++i)
	{
		register int x;
		cin >> x;
		while(q.front().first < i - k)
			q.pop_front();
		if(i == 1) printf("0\n");
		else printf("%d\n", q.front().second);
		while(q.size() && q.back().second >= x)
			q.pop_back();
		q.push_back({i, x});
	}
	return 0;
}

结果：
看了tj，恍然大悟，快读整上：

#include<bits/stdc++.h>
using namespace std;
deque<pair<int, int>> q;
inline int rd()
{
    int data = 0;
    int f = 1;
    char ch = getchar();
    while(ch < '0' || ch > '9')
    {
        if(ch == '-')
            f = -1;
        ch = getchar();
    }
    while(ch >= '0' && ch <= '9')
    {
        data = (data << 3) + (data << 1) + ch - '0';
        ch = getchar();
    }
    return f * data; 
}
int main()
{
	register int n, k;
	n = rd();
	k = rd();
	for(register int i = 1; i <= n; ++i)
	{
		register int x;
		x = rd();
		while(q.front().first < i - k)
			q.pop_front();
		if(i == 1) printf("0\n");
		else printf("%d\n", q.front().second);
		while(q.size() && q.back().second >= x)
			q.pop_back();
		q.push_back({i, x});
	}
	return 0;
}

结果：