Submission #240311

#	Time	Username	Problem	Language	Result	Execution time	Memory
240311		Coroian_David	Watching (JOI13_watching)	C++11	100 / 100	200 ms	16128 KiB

watching

#include <bits/stdc++.h>

#define MAX_N 2000

using namespace std;

int rez;

int n, p, q;
int a[MAX_N + 1 + 1];
int dp[MAX_N + 1][MAX_N + 1];

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

void init0()
{
    for(int i = 1; i <= n; i ++)
    {
        for(int j = 0; j <= n; j ++)
            dp[i][j] = -1;
    }
}

bool pos(int nr)
{
    init0();

    dp[1][q] = p;

    int dr[2] = {1, 1};
    int lim[2] = {nr, nr << 1};
    for(int i = 1; i <= n; i ++)
    {
        for(int h = 0; h <= 1; h ++)
        {
            while(dr[h] + 1 <= n && a[dr[h] + 1] - a[i] < lim[h])
                dr[h] ++;

            dr[h] ++;
        }

        for(int j = 0; j <= n; j ++)
        {
            if(dp[i][j] != -1)
            {
                if(j > 0 && dr[1] > n)
                    return 1;

                if(dr[0] > n && dp[i][j] > 0)
                    return 1;

                if(j > 0)
                    dp[dr[1]][j - 1] = max(dp[dr[1]][j - 1], dp[i][j]);

                if(dp[i][j] > 0)
                    dp[dr[0]][j] = max(dp[dr[0]][j], dp[i][j] - 1);
            }
        }

        dr[0] --;
        dr[1] --;

    }

    return 0;
}

int cautBin()
{
    int i = 0;
    int pas = 1 << 29;
    while(pas != 0)
    {
        if(pos(i + pas) == 0)
            i += pas;

        pas >>= 1;
    }

    return i + 1;
}

void solve()
{
    if(p + q >= n)
    {
        rez = 1;
        return;
    }

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

    rez = cautBin();
}

void printFile()
{
    cout << rez << "\n";
}

int main()
{
    readFile();

    solve();

    printFile();

    return 0;
}

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