大佬们，救救孩子吧

#include <bits/stdc++.h>
using namespace std;
const int N = 10000005;
int a[N];
deque<int>q;
int main() {
    int n,m;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)scanf("%d",&a[i]);
    for(int i=1;i<=n;i++){
        while(!q.empty()&&a[q.back()]>a[i])q.pop_back();
        q.push_back(i);
        if(i>=m){
            while(!q.empty()&&q.front()<=i-m);q.pop_front();
            printf("%d",a[q.front()]);
        }
    }
    printf("\n");
    while(!q.empty())q.pop_front();
    for(int i=1;i<=n;i++){
        while(!q.empty()&&a[q.back()]<a[i])q.pop_back();q.push_back(i);
        if(i>=m){
            while(!q.empty()&&q.front()<=i-m)q.pop_front();
            printf("%d",a[q.front()]);
        }
    }
    printf("\n");
    return 0;
}

大佬们，这玩意有什么问题啊，劳烦大佬们解答一下