Submission #967682

#	Time	Username	Problem	Language	Result	Execution time	Memory
967682		underwaterkillerwhale	Collecting Stamps 3 (JOI20_ho_t3)	C++17	100 / 100	74 ms	139384 KiB

ho_t3

#include <bits/stdc++.h>
#define se              second
#define fs              first
#define pb              push_back
#define ll              long long
#define ii              pair<ll,ll>
#define ld              long double
#define SZ(v)           (int)v.size()
#define ALL(v)          v.begin(), v.end()
#define bit(msk, i)     ((msk >> i) & 1)
#define iter(id, v)     for(auto id : v)
#define rep(i,m,n)      for(int i=(m); i<=(n); i++)
#define reb(i,m,n)      for(int i=(m); i>=(n); i--)

using namespace std;

mt19937_64 rd(chrono :: steady_clock :: now().time_since_epoch().count());
ll Rand(ll l, ll r) { return uniform_int_distribution<ll> (l, r)(rd); }

const int N = 2e2 + 7;
const ll Mod = 1e9 + 7;
const int szBL = 916;
const int INF = 2e9 + 7;
const int BASE = 137;

ll n, P;
ll a[N * 2], T[N * 2];
int dp[N * 2][N][N][2];

void minimize (int &a, ll b){ if (a > b) a = b;}

void solution () {
    cin >> n >> P;
    rep (i, 1, n) cin >> a[i];
    rep (i, 1, n) cin >> T[i];
    rep (i, n + 1, n * 2) a[i] = a[i - n], T[i] = T[i - n];
    memset(dp, 0x3f, sizeof dp);

    dp[n + 1][0][a[n + 1] <= T[n + 1]][1] = dp[n + 1][0][a[n + 1] <= T[n + 1]][0] = a[n + 1];
    dp[n][0][P - a[n] <= T[n]][1] = dp[n][0][P - a[n] <= T[n]][0] = P - a[n];

    reb (L, n + 1, 1) {
        rep (j, 1, n - 1) {
            int R = L + j;
            if (R < n) continue;
            rep (k, 0, n) {
                ll costRR = R == n + 1 ? P - a[R - 1] + a[R] : a[R] - a[R - 1];
                ll costLL = L == n ? a[L + 1] + P - a[L] : a[L + 1] - a[L];
                ll costLR = L == n + 1 ? a[R] - a[L] : P - a[L] + a[R];
                ll costRL = R == n ? a[R] - a[L] : P - a[L] + a[R];

                minimize (dp[L][j][k][1], costRR + dp[L][j - 1][k][1]);
                if (k > 0 && costRR + dp[L][j - 1][k - 1][1] <= T[R]) {
                    minimize (dp[L][j][k][1], costRR + dp[L][j - 1][k - 1][1]);
                }
                minimize(dp[L][j][k][1], costLR + dp[L][j - 1][k][0]);
                if (k > 0 && costLR + dp[L][j - 1][k - 1][0] <= T[R]) {
                    minimize (dp[L][j][k][1], costLR + dp[L][j - 1][k - 1][0]);
                }
                minimize(dp[L][j][k][0], costLL + dp[L + 1][j - 1][k][0]);
                if (k > 0 && costLL + dp[L + 1][j - 1][k - 1][0] <= T[L]) {
                    minimize (dp[L][j][k][0], costLL + dp[L + 1][j - 1][k - 1][0]);
                }
                minimize (dp[L][j][k][0], costRL + dp[L + 1][j - 1][k][1]);
                if (k > 0 && costRL + dp[L + 1][j - 1][k - 1][1] <= T[L]) {
                    minimize (dp[L][j][k][0], costRL + dp[L + 1][j - 1][k - 1][1]);
                }
//                rep (p, 0, 1)
//                    cout << L <<","<<j<<","<<k<<","<<p<<": "<<dp[L][j][k][p]<<" "<<dp[L][j - 1][k - 1][p] + costRR<<"\n";
            }
        }
    }
    int res = 0;
    rep (i, 1, n + 1)
    rep (j, 0, n - 1)
    rep (t, 0, n)
    rep (k, 0, 1) {
        if (dp[i][j][t][k] <= 1e9) res = max (res, t);
    }
    cout << res <<"\n";


}

#define file(name) freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout);

int main () {
//    file("c");
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    ll num_Test = 1;
//    cin >> num_Test;
    while(num_Test--)
        solution();
}
/*
5 20
4 5 8 13 17
18 23 15 7 10


*/

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