板子题之队列deque

洛谷P1886
代码简单记录下

#include "bits/stdc++.h"
using namespace std;
#define For(i,n) for(int i=1;i<=n;i++)
#define All(x) for(auto item:x)
const int N=2e6+10;
int n,m;
vector<int> arr(N),mi,ma;
void formi(){
    deque<int> tool;
    For(i,n){
        while(!tool.empty()&&arr[tool.back()]>=arr[i])
            tool.pop_back();
        tool.push_back(i);
        while(!tool.empty()&&tool.front()<=i-m)
            tool.pop_front();
        if(i>=m)
            mi.emplace_back(arr[tool.front()]);
    }
}
void forma(){
    deque<int> tool;
    For(i,n){
        while(!tool.empty()&&arr[tool.back()]<=arr[i])
            tool.pop_back();
        tool.push_back(i);
        while(!tool.empty()&&tool.front()<=i-m)
            tool.pop_front();
        if(i>=m)
            ma.emplace_back(arr[tool.front()]);
    }
}
inline void solve(){
    cin>>n>>m;
    For(i,n){cin>>arr[i];    }
    formi();
    forma();
    All(mi){cout<<item<<" ";    }
    cout<<endl;
    All(ma){cout<<item<<" ";    }
    cout<<endl;
}
int main(){
    int num=1;
    //cin>>num;
    solve();
    return 0;
}