oj.uz

Submission #66660

# Submission time Handle Problem Language Result Execution time Memory
66660 2018-08-12T03:55:37 Z HellAngel Watching (JOI13_watching) C++14
100 / 100
 70 ms 9268 KB 
#include <bits/stdc++.h>

using namespace std;

const int maxn = 2001;

int n, a[maxn], f[maxn][maxn], p, q, Next[maxn][2];

int bs(int x)
{
    int l = 1;
    int h = n;
    while(l <= h)
    {
        int mid = l + h >> 1;
        if(a[mid] < x) l = mid + 1;
        else h = mid - 1;
    }
    return l;
}

bool Check(int gau)
{
    for(int i = 1; i <= n; i++)
    {
        Next[i][0] = bs(a[i] + gau);
        Next[i][1] = bs(a[i] + 2 * gau);
    }
    f[0][0] = 1;
    for(int i = 0; i <= p; i++)
    {
        for(int j = 0; j <= q; j++)
        {
            if(i == 0 && j == 0) continue;
            int x = 0;
            if(i > 0)
            {
                x = max(x, Next[f[i - 1][j]][0]);
            }
            if(j > 0)
            {
                x = max(x, Next[f[i][j - 1]][1]);
            }
            if(x == n + 1) return true;
            f[i][j] = x;
        }
    }
    return false;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //freopen("test.inp", "r", stdin);
    //freopen("test.out", "w", stdout);
    cin >> n >> p >> q;
    for(int i = 1; i <= n; i++)
    {
        cin >> a[i];
    }
    sort(a + 1, a + n + 1);
    if(p + q >= n) return cout << 1, 0;
    int l = 1;
    int h = 1e9;
    while(l <= h)
    {
        int mid = (l + h) / 2;
        if(Check(mid)) h = mid - 1;
        else l = mid + 1;
    }
    cout << l;
}

Compilation message

watching.cpp: In function 'int bs(int)':
watching.cpp:15:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
         int mid = l + h >> 1;
                   ~~^~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 436 KB Output is correct
2 Correct 2 ms 436 KB Output is correct
3 Correct 3 ms 464 KB Output is correct
4 Correct 3 ms 640 KB Output is correct
5 Correct 2 ms 640 KB Output is correct
6 Correct 2 ms 640 KB Output is correct
7 Correct 2 ms 664 KB Output is correct
8 Correct 3 ms 744 KB Output is correct
9 Correct 2 ms 892 KB Output is correct
10 Correct 3 ms 892 KB Output is correct
11 Correct 3 ms 972 KB Output is correct
12 Correct 4 ms 972 KB Output is correct
13 Correct 2 ms 972 KB Output is correct
14 Correct 2 ms 972 KB Output is correct
15 Correct 3 ms 972 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 972 KB Output is correct
2 Correct 2 ms 972 KB Output is correct
3 Correct 3 ms 972 KB Output is correct
4 Correct 3 ms 972 KB Output is correct
5 Correct 3 ms 972 KB Output is correct
6 Correct 3 ms 972 KB Output is correct
7 Correct 6 ms 972 KB Output is correct
8 Correct 17 ms 1804 KB Output is correct
9 Correct 19 ms 4256 KB Output is correct
10 Correct 28 ms 9268 KB Output is correct
11 Correct 15 ms 9268 KB Output is correct
12 Correct 70 ms 9268 KB Output is correct
13 Correct 10 ms 9268 KB Output is correct
14 Correct 10 ms 9268 KB Output is correct
15 Correct 12 ms 9268 KB Output is correct