oj.uz

Submission #366312

# Submission time Handle Problem Language Result Execution time Memory
366312 2021-02-13T20:59:23 Z idk321 Watching (JOI13_watching) C++11
100 / 100
 314 ms 16236 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

const int N = 2005;
int dp[N][N];
int n,p, q;
int a[N];

bool poss(ll w)
{
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++) dp[i][j] = 0;
    }

    int next[N][2];
    for (int i = 0; i < 2; i++)
    {
        for (int j = 0; j < n; j++)
        {
            int first = a[j];
            int add = w - 1;
            if (i == 1) add += w;
            auto it = upper_bound(a, a + n, first + add);
            it--;
            next[j][i] = it - a + 1;
        }
    }
    for (int i = p; i >= 0; i--)
    {
        for (int j = q; j >= 0; j--)
        {

            if (dp[i][j] == n)
            {
                dp[0][0] = n;
            } else
            {
                if (i != 0)
                {
                    dp[i - 1][j] = max<int>(next[dp[i][j]][0], dp[i - 1][j]);
                }
                if (j != 0)
                {
                    dp[i][j - 1] = max<int>(next[dp[i][j]][1], dp[i][j  -1]);
                }
            }
        }
    }

    return dp[0][0] == n;
}

int bs()
{
    int a = 2;
    int b = 1000000000;

    int res = -1;
    while (a <= b)
    {
        int mid = (a + b) / 2;
        if (poss(mid))
        {
            res = mid;
            b = mid - 1;
        } else
        {
            a = mid + 1;
        }
    }

    return res;
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    cin >> n >> p >> q;
    for (int i = 0; i < n; i++) cin >> a[i];
    if (p + q >= n)
    {
        cout << 1 << "\n";
        return 0;
    }
    sort(a, a + n);

    cout << bs() << "\n";
}

/*
3 1 1
2
11
17
*/

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 139 ms 16108 KB Output is correct
2 Correct 0 ms 364 KB Output is correct
3 Correct 140 ms 16108 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 0 ms 364 KB Output is correct
6 Correct 0 ms 364 KB Output is correct
7 Correct 141 ms 16128 KB Output is correct
8 Correct 140 ms 16236 KB Output is correct
9 Correct 143 ms 16108 KB Output is correct
10 Correct 141 ms 16108 KB Output is correct
11 Correct 142 ms 16236 KB Output is correct
12 Correct 140 ms 16236 KB Output is correct
13 Correct 152 ms 16168 KB Output is correct
14 Correct 139 ms 16108 KB Output is correct
15 Correct 140 ms 16108 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 144 ms 16236 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 143 ms 16108 KB Output is correct
8 Correct 162 ms 16236 KB Output is correct
9 Correct 176 ms 16108 KB Output is correct
10 Correct 172 ms 16108 KB Output is correct
11 Correct 173 ms 16108 KB Output is correct
12 Correct 314 ms 16148 KB Output is correct
13 Correct 143 ms 16108 KB Output is correct
14 Correct 147 ms 16108 KB Output is correct
15 Correct 145 ms 16236 KB Output is correct