Submission #201950

#	Time	Username	Problem	Language	Result	Execution time	Memory
201950		kuroni	Collecting Stamps 3 (JOI20_ho_t3)	C++17	100 / 100	420 ms	131576 KiB

ho_t3

#include <bits/stdc++.h>
using namespace std;

const int N = 205;
const long long INF = 1E18 + 7;

int n, l, cur, le, ri, ans = 0, x[N], d[N];
long long dst, dp[N][N][N][2];

void mini(long long &cur, long long tmp) {
    if (tmp < cur) {
        cur = tmp;
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> n >> l;
    for (int i = 1; i <= n; i++) {
        cin >> x[i];
    }
    for (int i = 1; i <= n; i++) {
        cin >> d[i];
    }
    n++;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            for (int k = 0; k < n; k++) {
                dp[i][j][k][0] = dp[i][j][k][1] = INF;
            }
        }
    }
    dp[0][0][0][0] = 0;
    for (int k = 0; k < n; k++) {
        for (int len = 0; len < n; len++) {
            for (int i = 0; i < n; i++) {
                for (int t = 0; t < 2; t++) {
                    if (dp[i][len][k][t] == INF) {
                        continue;
                    }
                    cur = (t == 0 ? i : (i + len) % n);
                    le = (i + n - 1) % n;
                    ri = (i + len + 1) % n;
                    dst = min(l - abs(x[cur] - x[le]), abs(x[cur] - x[le])) + dp[i][len][k][t];
                    mini(dp[le][len + 1][k + (dst <= d[le])][0], dst);
                    dp[le][len + 1][k + (dst <= d[le])][0] = min(dp[le][len + 1][k + (dst <= d[le])][0], dst);
                    dst = min(l - abs(x[cur] - x[ri]), abs(x[cur] - x[ri])) + dp[i][len][k][t];
                    mini(dp[i][len + 1][k + (dst <= d[ri])][1], dst);
                    ans = max(ans, k);
                }
            }
        }
    }
    cout << ans;
}

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