Submission #1254601

#	Time	Username	Problem	Language	Result	Execution time	Memory
1254601		tvgk	Collecting Stamps 3 (JOI20_ho_t3)	C++20	100 / 100	40 ms	34120 KiB

ho_t3

#include<bits/stdc++.h>
using namespace std;
#define task "a"
#define se second
#define fi first
#define ll long long
#define ii pair<ll, ll>
const long mxN = 2e2 + 7, inf = 1e9 + 7;

int n, dp[mxN][mxN][mxN][2], l;
ii a[mxN];

int dis(int u, int v)
{
    return (v + l - u) % l;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
//    freopen(task".INP", "r", stdin);
//    freopen(task".OUT", "w", stdout);

    cin >> n >> l;
    for (int i = 1; i <= n; i++)
        cin >> a[i].fi;
    for (int i = 1; i <= n; i++)
        cin >> a[i].se;

    /*
    dp[i][j][k][dir] = min time
    phai la i
    trai la j
    ket qua la k
    dir = 0 ben phai
    dir = 1 ben trai
    */

    for (int i = 0; i <= n; i++)
    {
        for (int j = i + 1; j <= n + 1; j++)
        {
            for (int k = 0; k <= n; k++)
            {
                for (int dir = 0; dir <= 1; dir++)
                    dp[i][j][k][dir] = inf;
            }
        }
    }

    int ans = 0;
    dp[0][n + 1][0][0] = 0;
    for (int i = 0; i <= n; i++)
    {
        for (int j = n + 1; j > i; j--)
        {
            for (int k = 0; k <= n; k++)
            {
                for (int dir = 0; dir <= 1; dir++)
                {
                    if (dp[i][j][k][dir] == inf)
                        continue;

                    ans = max(ans, k);

                    int cur = a[i].fi;
                    if (dir)
                        cur = a[j].fi;

                    // den i + 1
                    int nw = dp[i][j][k][dir] + dis(cur, a[i + 1].fi);
                    dp[i + 1][j][k + (nw <= a[i + 1].se)][0] = min(dp[i + 1][j][k + (nw <= a[i + 1].se)][0], nw);

                    // den j - 1
                    nw = dp[i][j][k][dir] + dis(a[j - 1].fi, cur);
                    dp[i][j - 1][k + (nw <= a[j - 1].se)][1] = min(dp[i][j - 1][k + (nw <= a[j - 1].se)][1], nw);
                }
            }
        }
    }
    cout << ans;
}

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