Submission #1021687

#	Time	Username	Problem	Language	Result	Execution time	Memory
1021687		guagua0407	Hacker (BOI15_hac)	C++17	100 / 100	282 ms	22356 KiB

hac

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define f first
#define s second
#define all(x) x.begin(),x.end()
#define _ ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

int dx[4]={0,0,1,-1};
int dy[4]={1,-1,0,0};

void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}

const int inf=2e9+5;

int main() {_
    int n;
    cin>>n;
    vector<int> pre(2*n+1);
    vector<int> a(n+1);
    for(int i=1;i<=n;i++){
        cin>>a[i];
        pre[i]=a[i]+pre[i-1];
    }
    for(int i=n+1;i<=2*n;i++){
        pre[i]=pre[i-1]+a[i-n];
    }
    multiset<int> S;
    vector<int> mn(n+1,inf);
    int k=(n+1)/2;
    for(int i=1;i<=2*n;i++){
        if(i+k-1<=2*n){
            //cout<<"i "<<pre[i+k-1]-pre[i-1]<<'\n';
            S.insert(pre[i+k-1]-pre[i-1]);
        }
        if(i-1>=k){
            //cout<<"e "<<pre[i-1]-pre[i-1-k]<<'\n';
            S.erase(S.find(pre[i-1]-pre[i-1-k]));
        }
        int node=(i>n?i-n:i);
        if(!S.empty()) mn[node]=min(mn[node],*S.begin());
    }
    cout<<*max_element(mn.begin()+1,mn.end())<<'\n';
    return 0;
}
//maybe its multiset not set
//yeeorz
//laborz

Compilation message (stderr)

hac.cpp: In function 'void setIO(std::string)':
hac.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
hac.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 40 / 40