Submission #471006

#	Time	Username	Problem	Language	Result	Execution time	Memory
471006		iulia13	Watching (JOI13_watching)	C++14	100 / 100	287 ms	16012 KiB

watching

#include <bits/stdc++.h>

using namespace std;
const int N = 2e3 + 5;
int n, p, q;
int a[N];
int dp[N][N];
int check(int val)
{
    int i1 = 0, i2 = 0, i, j;
    for (i = 0; i <= n; i++)
        for (j = 0; j <= p; j++)
            dp[i][j] = q + 1;
    dp[0][0] = 0;
    for (i = 1; i <= n; i++)
    {
        while (a[i1 + 1] + val <= a[i])
            i1++;
        while (a[i2 + 1] + val * 2 <= a[i])
            i2++;
        for (j = 0; j <= p; j++)
        {
            if (j)
                dp[i][j] = min(dp[i][j], dp[i1][j - 1]);
            dp[i][j] = min(dp[i][j], dp[i2][j] + 1);
        }
    }
    for (i = 0; i <= p; i++)
        if (dp[n][i] <= q)
            return 1;
    return 0;
}
int main()
{
    int i, sol;
    cin >> n >> p >> q;
    p = min(p, n);
    q = min(q, n);
    for (i = 1; i <= n; i++)
        cin >> a[i];
    sort(a + 1, a + n + 1);
    int st = 1, dr = 1e9;
    while (st <= dr)
    {
        int mid = (st + dr) / 2;
        if (check(mid))
        {
            sol = mid;
            dr = mid - 1;
        }
        else
            st = mid + 1;
    }
    cout << sol;
    return 0;
}

Compilation message (stderr)

watching.cpp: In function 'int main()':
watching.cpp:54:13: warning: 'sol' may be used uninitialized in this function [-Wmaybe-uninitialized]
   54 |     cout << sol;
      |             ^~~

• Subtask 1: 50 / 50
• Subtask 2: 50 / 50