Submission #837457

#	Time	Username	Problem	Language	Result	Execution time	Memory
837457		green_gold_dog	Collecting Stamps 3 (JOI20_ho_t3)	C++17	0 / 100	1 ms	340 KiB

ho_t3

//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,sse,sse2,sse3,ssse3,sse4,abm,popcnt,mmx")
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef double db;
typedef long double ldb;
typedef complex<double> cd;

constexpr ll INF64 = 1'000'000'000'000'000'000, INF32 = 2'000'000'000, MOD = 1'000'000'007;
constexpr db PI = acos(-1);
constexpr bool IS_FILE = false, IS_TEST_CASES = false;

random_device rd;
mt19937 rnd32(rd());
mt19937_64 rnd64(rd());

template<typename T>
bool assign_max(T& a, T b) {
        if (b > a) {
                a = b;
                return true;
        }
        return false;
}

template<typename T>
bool assign_min(T& a, T b) {
        if (b < a) {
                a = b;
                return true;
        }
        return false;
}

template<typename T>
T square(T a) {
        return a * a;
}

template<>
struct std::hash<pair<ll, ll>> {
        ll operator() (pair<ll, ll> p) const {
                return ((__int128)p.first * MOD + p.second) % INF64;
        }
};

void solve() {
        ll n, l;
        cin >> n >> l;
        vector<ll> x(n);
        for (ll i = 0; i < n; i++) {
                cin >> x[i];
        }
        n += 2;
        x.push_back(l);
        x.insert(x.begin(), 0);
        vector<ll> need(n, 0);
        for (ll i = 1; i + 1 < n; i++) {
                cin >> need[i];
        }
        vector<vector<vector<ll>>> dp1(n, vector<vector<ll>>(n, vector<ll>(n, INF64))), dp2(n, vector<vector<ll>>(n, vector<ll>(n, INF64)));
        dp1[0][n - 1][0] = 0;
        dp2[0][n - 1][0] = 0;
        ll ans = 0;
        for (ll na = 0; na < n; na++) {
                for (ll i = 0; i < n; i++) {
                        for (ll j = n - 1; j >= 0; j--) {
                                if (i != 0 && na && dp1[i - 1][j][na - 1] + x[i] - x[i - 1] <= need[i]) {
                                        assign_min(dp1[i][j][na], dp1[i - 1][j][na - 1] + x[i] - x[i - 1]);
                                }
                                if (j != n - 1 && na && dp2[i][j + 1][na - 1] + x[j + 1] - x[j] <= need[j]) {
                                        assign_min(dp2[i][j][na], dp2[i][j + 1][na - 1] + x[j + 1] - x[j]);
                                }
                                if (i != 0 && na && dp2[i - 1][j][na - 1] + x[i] + l - x[j] <= need[i]) {
                                        assign_min(dp1[i][j][na], dp2[i - 1][j][na - 1] + x[i] + l - x[j]);
                                }
                                if (j != n - 1 && na && dp1[i][j + 1][na - 1] + x[i] + l - x[j] <= need[j]) {
                                        assign_min(dp2[i][j][na], dp1[i][j + 1][na - 1] + x[i] + l - x[j]);
                                }
                                if (i != 0) {
                                        assign_min(dp1[i][j][na], dp1[i - 1][j][na] + x[i] - x[i - 1]);
                                }
                                if (j != n - 1) {
                                        assign_min(dp2[i][j][na], dp2[i][j + 1][na] + x[j + 1] - x[j]);
                                }
                                if (i != 0) {
                                        assign_min(dp1[i][j][na], dp2[i - 1][j][na] + x[i] + l - x[j]);
                                }
                                if (j != n - 1) {
                                        assign_min(dp2[i][j][na], dp1[i][j + 1][na] + x[i] + l - x[j]);
                                }
                                if (dp1[i][j][na] < INF64) {
                                        assign_max(ans, na);
                                }
                                if (dp2[i][j][na] < INF64) {
                                        assign_max(ans, na);
                                }
                        }
                }
        }
        cout << ans << '\n';
}

int main() {
        if (IS_FILE) {
                freopen("", "r", stdin);
                freopen("", "w", stdout);
        }
        ios_base::sync_with_stdio(false);
        cin.tie(0);
        cout.tie(0);
        ll t = 1;
        if (IS_TEST_CASES) {
                cin >> t;
        }
        for (ll i = 0; i < t; i++) {
                solve();
        }
}

Compilation message (stderr)

ho_t3.cpp: In function 'int main()':
ho_t3.cpp:109:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  109 |                 freopen("", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~
ho_t3.cpp:110:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  110 |                 freopen("", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~

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