Submission #955852

#	Time	Username	Problem	Language	Result	Execution time	Memory
955852		Yang8on	Bigger segments (IZhO19_segments)	C++14	13 / 100	1 ms	4444 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;
int a[maxn];
ll s[maxn];
pii dp[maxn], ma[maxn];

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

    fi(i, 1, n) dp[i] = {0, 1e18};
    dp[0] = {0, 0}, ma[0] = {dp[0].first + 1, s[0]};

    fi(i, 1, n)
    {
        int l = 0, r = i - 1;
        while(l <= r)
        {
            int mid = (l + r) >> 1;
            if(dp[mid].second + s[mid] <= s[i]) l = mid + 1;
            else r = mid - 1;
        }

        dp[i] = {ma[r].first, s[i] - ma[r].second};
        ma[i] = max(ma[i - 1], make_pair(dp[i].first + 1, s[i]));
    }

    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:54:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   54 |         freopen(gsn".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
segments.cpp:55:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   55 |         freopen(gsn".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27