Submission #680904

#	Time	Username	Problem	Language	Result	Execution time	Memory
680904		SanguineChameleon	Collecting Stamps 3 (JOI20_ho_t3)	C++17	100 / 100	105 ms	83764 KiB

ho_t3

// BEGIN BOILERPLATE CODE

#include <bits/stdc++.h>
using namespace std;

#ifdef KAMIRULEZ
	const bool kami_loc = true;
	const long long kami_seed = 69420;
#else
	const bool kami_loc = false;
	const long long kami_seed = chrono::steady_clock::now().time_since_epoch().count();
#endif

const string kami_fi = "kamirulez.inp";
const string kami_fo = "kamirulez.out";
mt19937_64 kami_gen(kami_seed);

long long rand_range(long long rmin, long long rmax) {
	uniform_int_distribution<long long> rdist(rmin, rmax);
	return rdist(kami_gen);
}

long double rand_real(long double rmin, long double rmax) {
	uniform_real_distribution<long double> rdist(rmin, rmax);
	return rdist(kami_gen);
}

void file_io(string fi, string fo) {
	if (fi != "" && (!kami_loc || fi == kami_fi)) {
		freopen(fi.c_str(), "r", stdin);
	}
	if (fo != "" && (!kami_loc || fo == kami_fo)) {
		freopen(fo.c_str(), "w", stdout);
	}
}

void set_up() {
	if (kami_loc) {
		file_io(kami_fi, kami_fo);
	}
	ios_base::sync_with_stdio(0);
	cin.tie(0);
}

void just_do_it();

void just_exec_it() {
	if (kami_loc) {
		auto pstart = chrono::steady_clock::now();
		just_do_it();
		auto pend = chrono::steady_clock::now();
		long long ptime = chrono::duration_cast<chrono::milliseconds>(pend - pstart).count();
		string bar(50, '=');
		cout << '\n' << bar << '\n';
		cout << "Time: " << ptime << " ms" << '\n';
	}
	else {
		just_do_it();
	}
}

int main() {
	set_up();
	just_exec_it();
	return 0;
}

// END BOILERPLATE CODE

// BEGIN MAIN CODE

const int ms = 2e2 + 20;
const int inf = 1e9 + 20;
int dp[ms][ms][ms][2];
int X[ms];
int T[ms];

void just_do_it() {
	fill_n(&dp[0][0][0][0], ms * ms * ms * 2, inf);
	int N, L;
	cin >> N >> L;
	for (int i = 0; i < N; i++) {
		cin >> X[i];
	}
	for (int i = 0; i < N; i++) {
		cin >> T[i];
	}
	cin >> L;
	dp[0][0][0][0] = X[0];
	dp[0][0][1][0] = (X[0] <= T[0] ? X[0] : inf);
	dp[N - 1][N - 1][0][0] = L - X[N - 1];
	dp[N - 1][N - 1][1][0] = (L - X[N - 1] <= T[N - 1] ? L - X[N - 1] : inf);
	for (int i = 1; i < N; i++) {
		for (int j = 0; j < N; j++) {
			int lt = j;
			int rt = j + i - 1;
			if (rt >= N) {
				rt -= N;
			}
			for (int k = 0; k <= i; k++) {
				for (int l = 0; l < 2; l++) {
					if (dp[lt][rt][k][l] == inf) {
						continue;
					}
					int cur = (l == 0 ? lt : rt);
					int nl = (lt == 0 ? N - 1 : lt - 1);
					int dl = X[cur] - X[nl];
					if (dl < 0) {
						dl += L;
					}
					dl = min(dl, L - dl);
					dl += dp[lt][rt][k][l];
					int nr = (rt == N - 1 ? 0 : rt + 1);
					int dr = X[cur] - X[nr];
					if (dr < 0) {
						dr += L;
					}
					dr = min(dr, L - dr);
					dr += dp[lt][rt][k][l];;
					dp[nl][rt][k][0] = min(dp[nl][rt][k][0], dl);
					dp[nl][rt][k + 1][0] = min(dp[nl][rt][k + 1][0], (dl <= T[nl] ? dl : inf));
					dp[lt][nr][k][1] = min(dp[lt][nr][k][1], dr);
					dp[lt][nr][k + 1][1] = min(dp[lt][nr][k + 1][1], (dr <= T[nr] ? dr : inf));
				}
			}
		}
	}
	int res = 0;
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			for (int k = 0; k <= N; k++) {
				for (int l = 0; l < 2; l++) {
					if (dp[i][j][k][l] != inf) {
						res = max(res, k);
					}
				}
			}
		}
	}
	cout << res;
}

// END MAIN CODE

Compilation message (stderr)

ho_t3.cpp: In function 'void file_io(std::string, std::string)':
ho_t3.cpp:30:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |   freopen(fi.c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
ho_t3.cpp:33:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |   freopen(fo.c_str(), "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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