Submission #638577

#	Time	Username	Problem	Language	Result	Execution time	Memory
638577		ghostwriter	Watching (JOI13_watching)	C++14	100 / 100	405 ms	16032 KiB

watching

#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include <debug.h>
#endif
#define st first
#define nd second
#define pb push_back
#define pf push_front
#define _pb pop_back
#define _pf pop_front
#define lb lower_bound
#define ub upper_bound
#define mtp make_tuple
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
typedef long long ll; typedef unsigned long long ull;
typedef double db; typedef long double ldb;
typedef pair<int, int> pi; typedef pair<ll, ll> pll;
typedef vector<int> vi; typedef vector<ll> vll; typedef vector<pi> vpi; typedef vector<pll> vpll;
typedef string str;
template<typename T> T gcd(T a, T b) { return (b == 0? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
#define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
#define FOS(i, r, l) for (int (i) = (r); (i) >= (l); --(i))
#define EACH(i, x) for (auto &(i) : (x))
#define WHILE while
#define file "TEST"
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) { return uniform_int_distribution<ll>(l, r)(rd); }
/*
    Tran The Bao
    CTL - Da Lat
    Cay ngay cay dem nhung deo duoc cong nhan
*/
const int oo = 1e9;
const int N = 2e3 + 2;
int n, p, q, a[N], d[N][N], f[N], f1[N];
bool check(int w) {
	FOR(i, 1, n) {
		FOS(j, i, 1) {
			if (a[j] >= a[i] - w + 1) f[i] = j;
			if (a[j] >= a[i] - 2 * w + 1) f1[i] = j;
		}
	}
	FOR(i, 1, n)
	FOR(j, 0, p) {
		d[i][j] = oo;
		if (j) {
			int pos = f[i];
			d[i][j] = min(d[i][j], d[pos - 1][j - 1]);
		}
		int pos = f1[i];
		d[i][j] = min(d[i][j], d[pos - 1][j] + 1);
	}
	return d[n][p] <= q;
}
signed main() {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    // freopen(file".inp", "r", stdin);
    // freopen(file".out", "w", stdout);
    cin >> n >> p >> q;
    FOR(i, 1, n) cin >> a[i];
    sort(a + 1, a + 1 + n);
    p = min(p, n);
    q = min(q, n);
    int l = 1, r = 1e9, ans = -1;
    WHILE(l <= r) {
    	int mid = l + (r - l) / 2;
    	if (check(mid)) {
    		ans = mid;
    		r = mid - 1;
    	}
    	else l = mid + 1;
    }
    cout << ans;
    return 0;
}

Compilation message (stderr)

watching.cpp: In function 'bool check(int)':
watching.cpp:24:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   24 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
watching.cpp:40:2: note: in expansion of macro 'FOR'
   40 |  FOR(i, 1, n) {
      |  ^~~
watching.cpp:25:31: warning: unnecessary parentheses in declaration of 'j' [-Wparentheses]
   25 | #define FOS(i, r, l) for (int (i) = (r); (i) >= (l); --(i))
      |                               ^
watching.cpp:41:3: note: in expansion of macro 'FOS'
   41 |   FOS(j, i, 1) {
      |   ^~~
watching.cpp:24:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   24 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
watching.cpp:46:2: note: in expansion of macro 'FOR'
   46 |  FOR(i, 1, n)
      |  ^~~
watching.cpp:24:31: warning: unnecessary parentheses in declaration of 'j' [-Wparentheses]
   24 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
watching.cpp:47:2: note: in expansion of macro 'FOR'
   47 |  FOR(j, 0, p) {
      |  ^~~
watching.cpp: In function 'int main()':
watching.cpp:24:31: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   24 | #define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
      |                               ^
watching.cpp:63:5: note: in expansion of macro 'FOR'
   63 |     FOR(i, 1, n) cin >> a[i];
      |     ^~~

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