Submission #771462

#	Time	Username	Problem	Language	Result	Execution time	Memory
771462		horiiseun	Watching (JOI13_watching)	C++17	100 / 100	341 ms	31852 KiB

watching

#include <iostream>
#include <vector>
#include <tuple>
#include <queue>
#include <stack>
#include <deque>
#include <set>
#include <map>
#include <cmath>
#include <random>
#include <string>
#include <cassert>
#include <climits>
#include <algorithm>
#include <unordered_set>
#include <unordered_map>
using namespace std;

#define ll long long
#define f first
#define s second

void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template<typename A> void __print(const A &x);
template<typename A, typename B> void __print(const pair<A, B> &p);
template<typename... A> void __print(const tuple<A...> &t);
template<typename T> void __print(stack<T> s);
template<typename T> void __print(queue<T> q);
template<typename T, typename... U> void __print(priority_queue<T, U...> q);

template<typename A> void __print(const A &x) {
    bool first = true;
    cerr << '{';
    for (const auto &i : x) {
        cerr << (first ? "" : ","), __print(i);
        first = false;
    }
    cerr << '}';
}

template<typename A, typename B> void __print(const pair<A, B> &p) {
    cerr << '(';
    __print(p.f);
    cerr << ',';
    __print(p.s);
    cerr << ')';
}

template<typename... A> void __print(const tuple<A...> &t) {
    bool first = true;
    cerr << '(';
    apply([&first] (const auto &...args) { ((cerr << (first ? "" : ","), __print(args), first = false), ...); }, t);
    cerr << ')';
}

template<typename T> void __print(stack<T> s) {
    vector<T> debugVector;
    while (!s.empty()) {
        T t = s.top();
        debugVector.push_back(t);
        s.pop();
    }
    reverse(debugVector.begin(), debugVector.end());
    __print(debugVector);
}

template<typename T> void __print(queue<T> q) {
    vector<T> debugVector;
    while (!q.empty()) {
        T t = q.front();
        debugVector.push_back(t);
        q.pop();
    }
    __print(debugVector);
}

template<typename T, typename... U> void __print(priority_queue<T, U...> q) {
    vector<T> debugVector;
    while (!q.empty()) {
        T t = q.top();
        debugVector.push_back(t);
        q.pop();
    }
    __print(debugVector);
}

void _print() { cerr << "]\n"; }

template <typename Head, typename... Tail> void _print(const Head &H, const Tail &...T) {
    __print(H);
    if (sizeof...(T)) cerr << ", ";
    _print(T...);
}

#ifdef DEBUG
	#define D(...) cerr << "Line: " << __LINE__ << " [" << #__VA_ARGS__ << "] = ["; _print(__VA_ARGS__)
#else
	#define D(...)
#endif

int n, p, q, pos[2005][2];
ll l, r, dp[2005][2005];
vector<ll> a;

bool valid(ll x) {
	for (int j = 0, idx; j < 2; j++) {
		idx = 1;
		for (int i = 1; i <= n; i++) {
			while (a[idx] + (ll) (j + 1) * x - 1 < a[i]) {
				idx++;
			}
			pos[i][j] = idx;
		}
	}
	fill(&dp[0][0], &dp[0][0] + sizeof(dp) / sizeof(dp[0][0]), 1e12);
	dp[0][0] = 0;
	for (int i = 1; i <= n; i++) {
		for (int j = 0; j <= q; j++) {
			if (j) {
				dp[i][j] = min(dp[i][j], dp[pos[i][1] - 1][j - 1]);
			}
			dp[i][j] = min(dp[i][j], dp[pos[i][0] - 1][j] + 1);
		}
	}
	ll mn = 1e12;
	for (int i = 0; i <= q; i++) {
		mn = min(mn, dp[n][i]);
	}
	return mn <= p;
}

int main() {

	ios_base::sync_with_stdio(false);
	cin.tie(0);

	cin >> n >> p >> q;
	a.push_back(0);
	for (int i = 0, x; i < n; i++) {
		cin >> x;
		a.push_back(x);
	}
	sort(a.begin(), a.end());

	if (max(p, q) >= n) {
		cout << 1 << "\n";
		exit(0);
	}

	l = 0, r = 1e9;
	while (l + 1 != r) {
		ll m = (l + r) / 2;
		if (valid(m)) r = m;
		else l = m;
	}

	cout << r << "\n";

}

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