Submission #341536

#	Time	Username	Problem	Language	Result	Execution time	Memory
341536		iliccmarko	Watching (JOI13_watching)	C++14	100 / 100	428 ms	31980 KiB

watching

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl "\n"
#define INF 1000000000
#define LINF 1000000000000000LL
#define pb push_back
#define all(x) x.begin(), x.end()
#define len(s) (int)s.size()
#define test_case { int t; cin>>t; while(t--)solve(); }
#define single_case solve();
#define line cerr<<"----------"<<endl;
#define ios { ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); cerr.tie(NULL); }
#define mod 1000000007LL
ll n, p, q;
const int N = 2005;
vector<ll> a;
ll dp[N][N];



int main()
{
    ios
    cin>>n>>p>>q;
    a.pb(0);
    for(int i = 1;i<=n;i++)
    {
        ll x;
        cin>>x;
        a.pb(x);
    }
    sort(all(a));
    if(p+q>=n)
    {
        cout<<1;
        return 0;
    }

    ll ans = 1e9;
    ll l = 1;
    ll r = 1e9;
    while(l<=r)
    {
        ll mid = (r+l)/2;
        //mid = 4;
        for(int i = 0;i<=n;i++) for(int j = 0;j<=n;j++) dp[i][j] = INF;
        for(int i = 0;i<=n;i++) dp[0][i] = 0;
        for(int i = 1;i<=n;i++)
        {
            int w = a[i] - mid;
            int ind = upper_bound(all(a), w) - a.begin();
            if(ind)
            {
                ind--;
                for(int j = 0;j<=n;j++)
            {
                dp[i][j] = dp[ind][j] + 1;
            }
            }
            else
            {
                for(int j = 0;j<=n;j++)
                {
                    dp[i][j] = 1;
                    if(j) dp[i][j] = 0;
                }
            }
            ind = upper_bound(all(a), a[i] - 2*mid) - a.begin();
            if(ind)
            {
                ind--;
                for(int j = 1;j<=n;j++)
                {
                    dp[i][j] = min(dp[i][j], dp[ind][j-1]);
                }
            }
            else
            {
                for(int j = 1;j<=n;j++) dp[i][j] = 0;
            }
        }
        bool moze = false;
        for(int i = 0;i<=n;i++)
        {
            if(i<=q&&dp[n][i]<=p) moze = true;
        }
        /*for(int i = 1;i<=n;i++)
        {
            for(int j  = 0;j<=n;j++)
                cout<<dp[i][j]<<" ";
            cout<<endl;
        }*/
        if(moze)
        {
            ans = mid;
            r = mid - 1;
        }
        else
        {
            l = mid + 1;
        }
        //break;
    }

    cout<<ans;





    return 0;
}

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