Submission #862794

#	Time	Username	Problem	Language	Result	Execution time	Memory
862794		green_gold_dog	The Kingdom of JOIOI (JOI17_joioi)	C++17	0 / 100	0 ms	348 KiB

joioi

//#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 = 9'000'000'000'000'000'000, 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;
        }
};

bool check(ll n, ll m, vector<vector<ll>>& arr, ll x) {
        ll lst = m;
        for (ll i = 0; i < n; i++) {
                ll lo = lst;
                if (i) {
                        ll mi = -1, ma = -1;
                        for (ll j = 0; j < m; j++) {
                                if (abs(arr[i][j] - arr[i - 1][j]) > x) {
                                        if (mi == -1) {
                                                mi = j;
                                        }
                                        ma = j;
                                }
                        }
                        if (ma >= lst) {
                                return false;
                        }
                        if (mi != -1) {
                                lst = mi + 1;
                        }
                }
                for (ll j = 1; j < m; j++) {
                        if (abs(arr[i][j] - arr[i][j - 1]) > x) {
                                if (j > lst) {
                                        return false;
                                }
                                if (j == lo) {
                                        return false;
                                }
                                lst = j;
                        }
                }
        }
        return true;
}

ll sol(ll n, ll m, vector<vector<ll>>& arr) {
        ll l = -1, r = 1'000'000'000;
        while (r - l > 1) {
                ll mid = (l + r) / 2;
                if (check(n, m, arr, mid)) {
                        r = mid;
                } else {
                        l = mid;
                }
        }
        return r;
}

void solve() {
        ll n, m;
        cin >> n >> m;
        vector<vector<ll>> arr(n, vector<ll>(m));
        for (ll i = 0; i < n; i++) {
                for (ll j = 0; j < m; j++) {
                        cin >> arr[i][j];
                }
        }
        ll ans = sol(n, m, arr);
        reverse(arr.begin(), arr.end());
        cout << min(ans, sol(n, m, arr)) << '\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)

joioi.cpp: In function 'int main()':
joioi.cpp:115:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  115 |                 freopen("", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~
joioi.cpp:116:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  116 |                 freopen("", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 45
• Subtask 3: 0 / 40