Submission #1119935

#	Time	Username	Problem	Language	Result	Execution time	Memory
1119935		tintingyn21	Watching (JOI13_watching)	C++17	100 / 100	159 ms	16452 KiB

watching

// author : daohuyenchi



#ifdef LOCAL
    #include "D:\C++ Submit\debug.h"
#else
    #define debug(...)
#endif



#include <bits/stdc++.h>

using namespace std;

#define ull unsigned long long
#define db double
#define i32 int32_t  
#define i64 int64_t 
#define ll long long
// 
#define fi first
#define se second


//                                      #define int long long    // consider carefully


//
#define pii pair<int, int>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define pil pair<int, ll> 
#define PAIR make_pair 
//                                      TIME IS LIMITED ...  
#define  rep(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define repd(i, b, a) for (int i = (b), _a = (a); i >= _a; --i)
#define repv(v, H) for(auto &v: H)
//                                      REFLECT ON THE PAST ...
#define RESET(c, x) memset(c, x, sizeof(c))
#define MASK(i) (1LL << (i))
#define BIT(mask, i) (((mask) >> (i)) & 1LL)
#define ONBIT(mask, i) ((mask) | (1LL << (i)))
#define OFFBIT(mask, i) ((mask) &~ (1LL << (i)))
#define COUNTBIT __builtin_popcountll
//                                      30 / 1 / 2024 ? love is zero... start from zero 
#define vi vector <int>
#define vll vector <ll>
#define lwb lower_bound
#define upb upper_bound
#define all(v) (v).begin(), (v).end()
#define special(H) (H).resize(distance(H.begin(), unique(all(H))))
//                                      
#define sp ' ' 
#define nl '\n'
#define EL {cerr << '\n';}
#define yes "YES"
#define no "NO"
#define Log2(n) (63 - __builtin_clzll(n))
#define left __left__
#define right __right__ 
#define lps(id) ((id) << 1)
#define rps(id) ((id) << 1 | 1)

//____________________________________________________________________


template <class X, class Y> bool maximize(X &a, const Y &b) {
    if(a < b) return a = b, true;
    return false;
}

template <class X, class Y> bool minimize(X &a, const Y &b) {
    if(a > b) return a = b, true;
    return false;
}

template <class... T>
void print(T&&... n) {
    using exp = int[];
    exp{0, (cerr << n << sp, 0)...};
    cerr << nl;
}

template <class T, class... C>
void assign(int n, T v, C&&... a) {
    using e = int[];
    e{(a.assign(n, v), 0)...};
}

template <class... C>
void resize(int n, C&&... a) {
    using e = int[];
    e{(a.resize(n), 0)...};
}

template <class T>
using vector2d = vector<vector<T>>;
template <class T>
using vector3d = vector<vector2d<T>>;

template <class T> int ssize(T &a) { return (int) a.size(); }


//____________________________________________________________________


mt19937 rng(chrono::steady_clock().now().time_since_epoch().count());

const int MOD      = 1000000007;
// const int MOD[2] = {1000000009, 998244353};

template<class X> void modmize(X &x, int cur_Mod = MOD) {
    if(x >= cur_Mod) x -= cur_Mod;
    if(x < 0) x += cur_Mod;
}

const long long oo = 1e18 + 7;
const long long LINF = 1e18 + 7;
const int IINF      = 2e9;
const int nmax     = 2e3 + 10;
const int MAX      = 2e5;
const int base     = 311;
const db eps       = 1e-6;
const int block    = 500;
static const double PI = acos(-1.0);

//____________________________________________________________________


int n, P, Q;
int a[nmax];

int dp[nmax][nmax];

bool bin_check(int val) {
    vector2d <int> nxt(n + 2, vector <int>(2, 0));

    rep (i, 1, n) {
        repd (j, n, i) {
            if (a[j] - a[i] + 1 <= val && nxt[i][0] == 0) {
                nxt[i][0] = j;
            }
            if (a[j] - a[i] + 1 <= val * 2 && nxt[i][1] == 0) {
                nxt[i][1] = j;
            }
        }
    }

    rep (i, 0, n) rep (i2, 0, n) dp[i][i2] = 0;
    dp[1][0] = nxt[1][0];
    dp[0][1] = nxt[1][1];
    rep (i, 0, min(n, P)) {
        rep (j, 0, min(n, Q)) {
            if (dp[i][j] != 0 && dp[i][j] < n) {
                int cur = dp[i][j];
                maximize(dp[i + 1][j], max(cur, nxt[cur + 1][0]));
                maximize(dp[i][j + 1], max(cur, nxt[cur + 1][1]));
            }
        }
    } 

    rep (i, 0, min(n, P)) rep (j, 0, min(n, Q)) {
        if (dp[i][j] == n) return 1;
    }

    return 0;


}

void tintingyn() {

    cin >> n >> P >> Q;
    rep (i, 1, n) {
        cin >> a[i];
    }
    sort(a + 1, a + n + 1);

    int l = 1, r = 1e9;
    int res = -1;
    while (l <= r) {
        int mid = (l + r) / 2;
        if (bin_check(mid)) {
            res = mid;
            r = mid - 1;
        }
        else l = mid + 1;
    }

    cout << res << nl;

}

signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    //________________________________________________________________

    #define TASK "3"
    if(fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }

    //________________________________________________________________
    
    //  CODE FROM HERE ...! 





    int num_test = 1; 
    // cin >> num_test;

    while(num_test--) {

        tintingyn();

    }


    cerr << '\n' << "Time elapsed: " << (1.0 * clock() / CLOCKS_PER_SEC) << " s\n" << nl;

    return 0;
}

Compilation message (stderr)

watching.cpp: In function 'int main()':
watching.cpp:207:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  207 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
watching.cpp:208:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  208 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 50 / 50
• Subtask 2: 50 / 50