oj.uz

Submission #752558

# Submission time Handle Problem Language Result Execution time Memory
752558 2023-06-03T08:06:12 Z GrindMachine Hacker (BOI15_hac) C++17
100 / 100
 311 ms 19988 KB 
// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
https://github.com/Raghavan098/CP-Codes/blob/master/Baltic/Baltic%2015-hac.cpp

#of hacks = ceil(n/2)
#of protections = floor(n/2)

once hacker fixes index to hack, then protector can protect any segment of len = n/2 that he wants
idk proof

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

void solve(int test_case)
{
    ll n; cin >> n;
    vector<ll> a(n);
    rep(i,n) cin >> a[i];

    ll suma = 0;
    rep(i,n) suma += a[i];

    vector<ll> sum_here(n);

    ll sum = 0;
    rep(i,n/2) sum += a[i];

    rep(l,n){
        ll r = (l+n/2-1)%n;
        if(l){
            sum += a[r];
            sum -= a[l-1];
        }

        sum_here[l] = sum;
    }

    multiset<ll> ms;
    rep(l,n){
        if(l > 0 and (l+n/2-1) < n){
            ms.insert(sum_here[l]);
        }
    }

    ll ans = 0;

    rep(hack,n){
        if(hack){
            ms.erase(ms.find(sum_here[hack]));
            ll addl = (hack-n/2+n) % n;
            ms.insert(sum_here[addl]);
        }

        ll val = suma - *ms.rbegin();
        amax(ans, val);
    }

    cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 0 ms 212 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 1 ms 212 KB Output is correct
18 Correct 0 ms 212 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 0 ms 212 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 1 ms 212 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 1 ms 212 KB Output is correct
20 Correct 1 ms 340 KB Output is correct
21 Correct 1 ms 340 KB Output is correct
22 Correct 2 ms 468 KB Output is correct
23 Correct 2 ms 488 KB Output is correct
24 Correct 2 ms 340 KB Output is correct
25 Correct 2 ms 468 KB Output is correct
26 Correct 2 ms 468 KB Output is correct
27 Correct 0 ms 212 KB Output is correct
28 Correct 0 ms 212 KB Output is correct
29 Correct 0 ms 212 KB Output is correct
30 Correct 2 ms 468 KB Output is correct
31 Correct 2 ms 468 KB Output is correct

Subtask #3
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 2 ms 468 KB Output is correct
4 Correct 31 ms 3384 KB Output is correct
5 Correct 93 ms 8112 KB Output is correct
6 Correct 117 ms 10100 KB Output is correct
7 Correct 129 ms 12020 KB Output is correct
8 Correct 311 ms 19972 KB Output is correct

Subtask #4
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 212 KB Output is correct
9 Correct 0 ms 212 KB Output is correct
10 Correct 1 ms 212 KB Output is correct
11 Correct 1 ms 212 KB Output is correct
12 Correct 1 ms 212 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 0 ms 212 KB Output is correct
15 Correct 0 ms 212 KB Output is correct
16 Correct 1 ms 212 KB Output is correct
17 Correct 1 ms 212 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 1 ms 212 KB Output is correct
20 Correct 1 ms 340 KB Output is correct
21 Correct 1 ms 340 KB Output is correct
22 Correct 2 ms 468 KB Output is correct
23 Correct 2 ms 488 KB Output is correct
24 Correct 2 ms 340 KB Output is correct
25 Correct 2 ms 468 KB Output is correct
26 Correct 2 ms 468 KB Output is correct
27 Correct 0 ms 212 KB Output is correct
28 Correct 0 ms 212 KB Output is correct
29 Correct 0 ms 212 KB Output is correct
30 Correct 2 ms 468 KB Output is correct
31 Correct 2 ms 468 KB Output is correct
32 Correct 0 ms 212 KB Output is correct
33 Correct 0 ms 212 KB Output is correct
34 Correct 2 ms 468 KB Output is correct
35 Correct 31 ms 3384 KB Output is correct
36 Correct 93 ms 8112 KB Output is correct
37 Correct 117 ms 10100 KB Output is correct
38 Correct 129 ms 12020 KB Output is correct
39 Correct 311 ms 19972 KB Output is correct
40 Correct 4 ms 596 KB Output is correct
41 Correct 9 ms 1108 KB Output is correct
42 Correct 11 ms 1492 KB Output is correct
43 Correct 89 ms 8040 KB Output is correct
44 Correct 255 ms 19844 KB Output is correct
45 Correct 38 ms 4180 KB Output is correct
46 Correct 136 ms 12020 KB Output is correct
47 Correct 283 ms 19848 KB Output is correct
48 Correct 229 ms 19988 KB Output is correct
49 Correct 213 ms 19852 KB Output is correct
50 Correct 215 ms 19788 KB Output is correct