题目描述
滑动窗口求最值
输入样例
8 3
1 3 -1 -3 5 3 6 7
输出样例
-1 -3 -3 -3 3 3
3 3 5 5 6 7
算法1
(单调队列) $O(n)$
blablabla
时间复杂度 $O(n)$
C++ 代码
#include <iostream>
using namespace std;
const int N = 1e6 + 7;
int n,k,a[N],q[N],p[N];
int main()
{
cin >> n >> k;
for(int i = 1; i <= n; i ++)cin >> a[i];
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)cout << q[head] << " ";
}
cout << endl;
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)cout << q[head] << " ";
}
return 0;
}
算法2
(暴力枚举) $O(n^2)$
blablabla
时间复杂度
参考文献
C++ 代码
blablabla