Submission #1270581

#	Time	Username	Problem	Language	Result	Execution time	Memory
1270581		nathan4690	Hacker (BOI15_hac)	C++20	100 / 100	227 ms	35672 KiB

hac

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define f1(i,n) for(int i=1;i<=n;i++)
#define __file_name ""
using namespace std;
const ll maxn = 2e6+5, inf=1e18;

ll n, a[maxn], pf[maxn], cnt, ans;
multiset<ll> S;

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);

    if(fopen(__file_name ".inp", "r")){
        freopen(__file_name ".inp","r",stdin);
        freopen(__file_name ".out","w",stdout);
    }
    // code here
    cin >> n;
    f1(i,n) cin >> a[i];
    cnt = (n + 1) / 2;
    for(int i=n+1;i<=3*n;i++) a[i] = a[i - n];
    f1(i, 3*n) pf[i] = pf[i-1] + a[i];
    for(int i=n+1;i<=n+cnt;i++){
        S.insert(pf[i] - pf[i - cnt]);
    }
    ans = *S.begin();
    for(int i=n+2;i<=2*n;i++){
        S.erase(S.find(pf[i-1] - pf[i - cnt - 1]));
        S.insert(pf[i + cnt - 1] - pf[i - 1]);
        ans = max(ans, *S.begin());
//        cout << S.size() << '\n';
    }
    cout << ans;
    return 0;
}

Compilation message (stderr)

hac.cpp: In function 'int main()':
hac.cpp:16:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |         freopen(__file_name ".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
hac.cpp:17:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |         freopen(__file_name ".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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