Submission #1053892

#	Time	Username	Problem	Language	Result	Execution time	Memory
1053892		SamAnd	Bikeparking (EGOI24_bikeparking)	C++17	100 / 100	146 ms	8016 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define fi first
#define se second
typedef long long ll;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
mt19937 rnf(2106);
const int N = 300005;
const int INF = 1000000009;

int n;
int x[N], y[N];
int cx[N], cy[N];

int stg(int p, int& q)
{
    for (int i = 1; i <= n; ++i)
    {
        cx[i] = x[i];
        cy[i] = y[i];
    }

    int ans = -p;

    int s = p;
    for (int i = n; i >= 1; --i)
    {
        if (x[i] >= s)
        {
            x[i] -= s;
            s = 0;
        }
        else
        {
            s -= x[i];
            x[i] = 0;
        }
    }
    assert(s == 0);

    s = p;
    for (int i = 1; i <= n; ++i)
    {
        if (y[i] >= s)
        {
            y[i] -= s;
            s = 0;
        }
        else
        {
            s -= y[i];
            y[i] = 0;
        }
    }
    assert(s == 0);

    int i = 1;
    int j = 1;
    while (i <= n && j <= n)
    {
        if (x[i] == 0)
        {
            ++i;
            continue;
        }
        if (y[j] == 0)
        {
            ++j;
            continue;
        }
        if (i > j)
        {
            for (int i = 1; i <= n; ++i)
            {
                x[i] = cx[i];
                y[i] = cy[i];
            }
            return -INF;
        }
        int minu = min(x[i], y[j]);
        if (x[i] >= y[j])
        {
            x[i] -= y[j];
            y[j] = 0;
        }
        else
        {
            y[j] -= x[i];
            x[i] = 0;
        }
        if (i < j)
            ans += minu;
        else
            ++q;
    }

    for (int i = 1; i <= n; ++i)
    {
        x[i] = cx[i];
        y[i] = cy[i];
    }

    return ans;
}

void solv()
{
    n = rnd() % 10 + 1;
    for (int i = 1; i <= n; ++i)
        x[i] = rnd() % 20;
    for (int i = 1; i <= n; ++i)
        y[i] = rnd() % 20;

    int ss = 0;
    for (int i = 1; i <= n; ++i)
        ss += x[i];
    for (int i = 1; i <= n; ++i)
        ss -= y[i];
    if (ss < 0)
    {
        for (int i = 1; i <= n; ++i)
            swap(x[i], y[i]);
    }

    cin >> n;
    for (int i = 1; i <= n; ++i)
        cin >> x[i];
    for (int i = 1; i <= n; ++i)
        cin >> y[i];

    int s = 0;
    for (int i = 1; i <= n; ++i)
        s += x[i];
    for (int i = 1; i <= n; ++i)
        s -= y[i];
    assert(s >= 0);

    for (int i = n; i >= 1; --i)
    {
        if (x[i] >= s)
        {
            x[i] -= s;
            s = 0;
        }
        else
        {
            s -= x[i];
            x[i] = 0;
        }
    }
    assert(s == 0);

    for (int i = 1; i <= n; ++i)
        s += x[i];

    int ans = -s;
    /*for (int p = 0; p <= s; ++p)
    {
        ans = max(ans, stg(p));
        cout << stg(p) << ' ';
    }
    cout << "\n";*/

    int l = 0, r = s;
    int u;
    while (l <= r)
    {
        int m = (l + r) / 2;
        int q = 0;
        if (stg(m, q) > -INF)
        {
            u = m;
            r = m - 1;
        }
        else
            l = m + 1;
    }

    l = u, r = s;
    while (l <= r)
    {
        int m = (l + r) / 2;
        int q = 0;
        ans = max(ans, stg(m, q));
        if (q > 1)
        {
            l = m + 1;
        }
        else
        {
            r = m - 1;
        }
    }

    cout << ans << "\n";
}

int main()
{
    #ifdef SOMETHING
    freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    #endif // SOMETHING
    ios_base::sync_with_stdio(false), cin.tie(0);

    int tt = 1;
    //cin >> tt;
    while (tt--)
    {
        solv();
    }
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'void solv()':
Main.cpp:185:20: warning: 'u' may be used uninitialized in this function [-Wmaybe-uninitialized]
  185 |         int m = (l + r) / 2;
      |                 ~~~^~~~

• Subtask 1: 16 / 16
• Subtask 2: 9 / 9
• Subtask 3: 19 / 19
• Subtask 4: 24 / 24
• Subtask 5: 32 / 32