oj.uz

Submission #934609

# Submission time Handle Problem Language Result Execution time Memory
934609 2024-02-27T16:54:59 Z borisAngelov Watching (JOI13_watching) C++17
100 / 100
 495 ms 16368 KB 
#include <bits/stdc++.h>

using namespace std;

const int maxn = 2005;
const int inf = 1e9;

int n, p, q;

int a[maxn];

int findPos(int pos, int delta)
{
    int l = 1;
    int r = pos;

    while (l <= r)
    {
        int mid = (l + r) / 2;

        if (a[pos] - a[mid] <= delta)
        {
            r = mid - 1;
        }
        else
        {
            l = mid + 1;
        }
    }

    return l;
}

int prvSmall[maxn];
int prvBig[maxn];

int dp[maxn][maxn];

bool check(int w)
{
    for (int i = 1; i <= n; ++i)
    {
        prvSmall[i] = findPos(i, w - 1);
        prvBig[i] = findPos(i, 2 * w - 1);
    }

    for (int pos = 1; pos <= n; ++pos)
    {
        for (int currp = 0; currp <= p; ++currp)
        {
            dp[pos][currp] = inf;
            dp[pos][currp] = min(dp[pos][currp], dp[prvBig[pos] - 1][currp] + 1);

            if (currp >= 1)
            {
                dp[pos][currp] = min(dp[pos][currp], dp[pos][currp - 1]);
                dp[pos][currp] = min(dp[pos][currp], dp[prvSmall[pos] - 1][currp - 1]);
            }
        }
    }

    for (int i = 0; i <= p; ++i)
    {
        if (dp[n][i] <= q)
        {
            return true;
        }
    }

    return false;
}

void fastIO()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int main()
{
    fastIO();

    cin >> n >> p >> q;

    for (int i = 1; i <= n; ++i)
    {
        cin >> a[i];
    }

    if (q >= n || p >= n)
    {
        cout << 1 << endl;
        return 0;
    }

    sort(a + 1, a + n + 1);

    int l = 1;
    int r = 1000000000;

    while (l <= r)
    {
        int mid = (l + r) / 2;

        if (check(mid) == true)
        {
            r = mid - 1;
        }
        else
        {
            l = mid + 1;
        }
    }

    cout << l << endl;

    return 0;
}

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2396 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 1 ms 2396 KB Output is correct
8 Correct 1 ms 2396 KB Output is correct
9 Correct 1 ms 2396 KB Output is correct
10 Correct 1 ms 2396 KB Output is correct
11 Correct 1 ms 2396 KB Output is correct
12 Correct 1 ms 2396 KB Output is correct
13 Correct 1 ms 2396 KB Output is correct
14 Correct 1 ms 2396 KB Output is correct
15 Correct 1 ms 2396 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 15452 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 385 ms 16180 KB Output is correct
4 Correct 1 ms 348 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 10 ms 15452 KB Output is correct
8 Correct 38 ms 15452 KB Output is correct
9 Correct 199 ms 16032 KB Output is correct
10 Correct 495 ms 16368 KB Output is correct
11 Correct 28 ms 15452 KB Output is correct
12 Correct 259 ms 16180 KB Output is correct
13 Correct 7 ms 15452 KB Output is correct
14 Correct 8 ms 15452 KB Output is correct
15 Correct 8 ms 15452 KB Output is correct