Submission #552784

#	Time	Username	Problem	Language	Result	Execution time	Memory
552784		toastifishi	Collecting Stamps 3 (JOI20_ho_t3)	C++14	100 / 100	147 ms	132076 KiB

ho_t3

#include <bits/stdc++.h> 
#define x first
#define y second
using namespace std;
using ll = long long;
int n, L;
const int MAXN = 205;
ll dp[MAXN][MAXN][2][MAXN];
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    cin >> n >> L;
    vector <ll> x(n + 2), t(n + 2);
    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 k = 0; k < 2; k++) {
                for(int m = 0; m <= n; m++) dp[i][j][k][m] = 1e18;
            }
        }
    }
    dp[0][n + 1][0][0] = dp[0][n + 1][1][0] = 0;
    for(int i = 0; i < n; i++) {
        for(int j = n + 1; j >= i + 2; j--) {
            for(int m = 0; m <= n; m++) {
                ll T;
                T = min(dp[i][j][0][m] + x[i + 1] - x[i], dp[i][j][1][m] + x[i + 1] + L - x[j]);
                dp[i + 1][j][0][m + (T <= t[i + 1])] = min(dp[i + 1][j][0][m + (T <= t[i + 1])], T);
                T = min(dp[i][j][0][m] + x[i] + L - x[j - 1], dp[i][j][1][m] + x[j] - x[j - 1]);
                dp[i][j - 1][1][m + (T <= t[j - 1])] = min(dp[i][j - 1][1][m + (T <= t[j - 1])], T);
            }
        }
    }
    ll ans = 0;
    for(int i = 0; i <= n + 1; i++) {
        for(int j = 0; j <= n + 1; j++) {
            for(int k = 0; k < 2; k++) {
                for(int m = 0; m <= n; m++) {
                    if(dp[i][j][k][m] != 1e18) ans = max(ans, (ll)m);
                }
            }
        }
    }
    cout << ans << "\n";
    return 0;
}

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