Submission #956098

#	Time	Username	Problem	Language	Result	Execution time	Memory
956098		vjudge1	Bigger segments (IZhO19_segments)	C++17	100 / 100	115 ms	47188 KiB

segments

#include <bits/stdc++.h>
#define gsn "Bigger segments"
#define ll long long
#define pii pair<int, ll>
#define gb(i, j) ((i >> j) & 1)
#define fi(i, a, b) for(int i = a; i <= b; i++)
#define fid(i, a, b) for(int i = a; i >= b; i--)

using namespace std;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll GetRandom(ll l, ll r)
{
    return uniform_int_distribution<ll> (l, r) (rng);
}

const int maxn = 500005;

int n;
ll a[maxn], s[maxn];
pii dp[maxn];

void solve()
{
    cin >> n;
    fi(i, 1, n) cin >> a[i], s[i] = s[i - 1] + a[i];

    multiset<pair<ll, pii>> se;
    pii ma = {1, s[0]};

    fi(i, 1, n)
    {
        dp[i] = {ma.first, s[i] - ma.second};
        se.insert({ dp[i].second + s[i], make_pair(dp[i].first + 1, s[i]) });

        while(se.size())
        {
            auto it = se.begin();
            if(it->first <= s[i + 1])
            {
                se.erase(it);
                ma = max(ma, it->second);
            }
            else break;
        }
    }

    cout << dp[n].first;
}


int main()
{
    if(fopen(gsn".inp", "r"))
    {
        freopen(gsn".inp", "r", stdin);
        freopen(gsn".out", "w", stdout);
    }

    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);

    int nTest = 1;
//    cin >> nTest;

    while(nTest --)
    {
        solve();
    }




    /// ------------------check time!-----------------///
    cerr << "\n" << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";
    return 0;
}

Compilation message (stderr)

segments.cpp: In function 'int main()':
segments.cpp:56:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   56 |         freopen(gsn".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
segments.cpp:57:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |         freopen(gsn".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 14 / 14
• Subtask 3: 10 / 10
• Subtask 4: 36 / 36
• Subtask 5: 27 / 27