Submission #924579

#	Time	Username	Problem	Language	Result	Execution time	Memory
924579		qwe1rt1yuiop1	Collecting Stamps 3 (JOI20_ho_t3)	C++14	15 / 100	649 ms	322968 KiB

ho_t3

#include <bits/stdc++.h>
#define int long long
using namespace std;
using pii = pair<int, int>;

int n, l;

vector<int> x, t;

int dis(int a, int b)
{
    assert(0 <= a && 0 <= b && a <= n && b <= n);
    return min(min(abs(x[a] - x[b]), x[a] + l - x[b]), l - x[a] + x[b]);
}

void solve()
{
    cin >> n >> l;
    x.assign(n + 1, 0), t.assign(n + 1, -1);
    for (int i = 1; i <= n; ++i)
        cin >> x[i];
    for (int i = 1; i <= n; ++i)
        cin >> t[i];

    vector<vector<vector<vector<int>>>> dp(n + 1, vector<vector<vector<int>>>(n + 1, vector<vector<int>>(n + 1, vector<int>(2, LONG_LONG_MAX))));
    dp[0][0][0][0] = dp[0][0][0][1] = 0;

    for (int a = 0; a < 10; ++a)
    for (int i = 0; i < n; ++i)
        for (int j = 0; j <= n; ++j)
            for (int k = 0; k <= n; ++k)
            {
                if (dp[i][j][k][0] != LONG_LONG_MAX)
                {
                    if ((j + n) % (n + 1) != k)
                    {
                        dp[i][(j + n) % (n + 1)][k][0] = min(dp[i][(j + n) % (n + 1)][k][0], dp[i][j][k][0] + dis(j, (j + n) % (n + 1)));
                        if (dp[i][j][k][0] + dis(j, (j + n) % (n + 1)) <= t[(j + n) % (n + 1)])
                            dp[i + 1][(j + n) % (n + 1)][k][0] = min(dp[i + 1][(j + n) % (n + 1)][k][0], dp[i][j][k][0] + dis(j, (j + n) % (n + 1)));
                    }
                    if (j != (k + 1) % (n + 1))
                    {
                        dp[i][j][(k + 1) % (n + 1)][1] = min(dp[i][j][(k + 1) % (n + 1)][1], dp[i][j][k][0] + dis(j, (k + 1) % (n + 1)));
                        if (dp[i][j][k][0] + dis(j, (k + 1) % (n + 1)) <= t[(k + 1) % (n + 1)])
                            dp[i + 1][j][(k + 1) % (n + 1)][1] = min(dp[i + 1][j][(k + 1) % (n + 1)][1], dp[i][j][k][0] + dis(j, (k + 1) % (n + 1)));
                    }
                }
                if (dp[i][j][k][1] != LONG_LONG_MAX)
                {
                    if ((j + n) % (n + 1) != k)
                    {
                        dp[i][(j + n) % (n + 1)][k][0] = min(dp[i][(j + n) % (n + 1)][k][0], dp[i][j][k][1] + dis(k, (j + n) % (n + 1)));
                        if (dp[i][j][k][1] + dis(k, (j + n) % (n + 1)) <= t[(j + n) % (n + 1)])
                            dp[i + 1][(j + n) % (n + 1)][k][0] = min(dp[i + 1][(j + n) % (n + 1)][k][0], dp[i][j][k][1] + dis(k, (j + n) % (n + 1)));
                    }
                    if (j != (k + 1) % (n + 1))
                    {
                        dp[i][j][(k + 1) % (n + 1)][1] = min(dp[i][j][(k + 1) % (n + 1)][1], dp[i][j][k][1] + dis(k, (k + 1) % (n + 1)));
                        if (dp[i][j][k][1] + dis(k, (k + 1) % (n + 1)) <= t[(k + 1) % (n + 1)])
                            dp[i + 1][j][(k + 1) % (n + 1)][1] = min(dp[i + 1][j][(k + 1) % (n + 1)][1], dp[i][j][k][1] + dis(k, (k + 1) % (n + 1)));
                    }
                }
            }

    int ans = 0;
    for (int i = 0; i <= n; ++i)
        for (int j = 0; j <= n; ++j)
            for (int k = 0; k <= n; ++k)
                for (int l = 0; l < 2; ++l)
                    if (dp[i][j][k][l] != LONG_LONG_MAX)
                        ans = max(ans, i);
    cout << ans << '\n';
}

/*
6 25
3 4 7 17 21 23
11 7 17 10 8 10

5 20
4 5 8 13 17
18 23 15 7 10

4 19
3 7 12 14
2 0 5 4

10 87
9 23 33 38 42 44 45 62 67 78
15 91 7 27 31 53 12 91 89 46

 */

signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    solve();

    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 75