Submission #639890

#	Time	Username	Problem	Language	Result	Execution time	Memory
639890		danikoynov	Collecting Stamps 3 (JOI20_ho_t3)	C++14	100 / 100	176 ms	135268 KiB

ho_t3

/**
 ____ ____ ____ ____ ____ ____
||l |||e |||i |||n |||a |||d ||
||__|||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|/__\|

**/

#include<bits/stdc++.h>
#define endl '\n'

using namespace std;
typedef long long ll;

void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}

const int maxn = 210;
const ll inf = 1e18;

int n;
ll l, x[maxn], t[maxn], dp[maxn][maxn][maxn][2];
void solve()
{
    cin >> n >> l;
    for (int i = 1; i <= n; i ++)
        cin >> x[i];
    for (int i = 1; i <= n; i ++)
        cin >> t[i];
    x[n + 1] = l;

    for (int i = 0; i <= n + 1; i ++)
        for (int j = 0; j <= n + 1; j ++)
            for (int f = 0; f <= n + 1; f ++)
                dp[i][j][f][0] = dp[i][j][f][1] = inf;

    dp[0][n + 1][0][0] = dp[0][n + 1][0][1] = 0;

    ll ans = 0;
    for (int f = 0; f <= n + 1; f ++)
    {
        for (int d = n; d > 0; d --)
        {

            for (int i = 0; i <= n - d + 1; i ++)
            {
                int j = i + d;


                if (i != 0)
                {
                    dp[i][j][f][0] = min(dp[i][j][f][0], dp[i - 1][j][f][0] + x[i] - x[i - 1]);
                    if (f > 0)
                    {
                        ll tp = dp[i - 1][j][f - 1][0] + x[i] - x[i - 1];
                        if (tp <= t[i])
                            dp[i][j][f][0] = min(dp[i][j][f][0], tp);
                    }
                }
                if (j != n + 1)
                {
                    dp[i][j][f][1] = min(dp[i][j][f][1], dp[i][j + 1][f][1] + x[j + 1] - x[j]);
                    if (f > 0)
                    {
                        ll tp = dp[i][j + 1][f - 1][1] + x[j + 1] - x[j];
                        if (tp <= t[j])
                        {
                            dp[i][j][f][1] = min(dp[i][j][f][1], tp);
                        }
                    }
                }

                if (dp[i][j][f][0] + x[i] + l - x[j] < dp[i][j][f][1])
                    dp[i][j][f][1] = dp[i][j][f][0] + x[i] + l - x[j];

                if (dp[i][j][f][1] + x[i] + l - x[j] < dp[i][j][f][0])
                    dp[i][j][f][0] = dp[i][j][f][1] + x[i] + l - x[j];

                if (dp[i][j][f][0] != inf || dp[i][j][f][1] != inf)
                    ans = max(ans, (ll)f);

                ///cout << i << " " << j << " " << f << " " << dp[i][j][f][0] << " " << dp[i][j][f][1] << endl;
            }
        }
    }
    cout << ans << endl;
}

int main()
{
    solve();
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 75 / 75