Submission #606865

#	Time	Username	Problem	Language	Result	Execution time	Memory
606865		SanguineChameleon	Skyscraper (JOI16_skyscraper)	C++14	100 / 100	104 ms	20208 KiB

skyscraper

// 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);
}

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 mod = 1e9 + 7;
int dp[101][101][1001][2][2];
int h[100];

void just_do_it() {
	int n, l;
	cin >> n >> l;
	for (int i = 0; i < n; i++) {
		cin >> h[i];
	}
	sort(h, h + n);
	dp[1][1][0][0][0] = 1;
	dp[1][1][0][1][0] = 1;
	dp[1][1][0][0][1] = 1;
	dp[1][1][0][1][1] = 1;
	for (int p = 1; p < n; p++) {
		for (int a = 1; a <= n; a++) {
			for (int b = 0; b <= l; b++) {
				for (int c = 0; c <= 1; c++) {
					for (int d = 0; d <= 1; d++) {
						if (dp[p][a][b][c][d] == 0) {
							continue;
						}
						int nb = b + (h[p] - h[p - 1]) * (a * 2 - c - d);
						if (nb > l) {
							continue;
						}
						int s = dp[p][a][b][c][d];
						dp[p + 1][a][nb][c][d] += (long long)s * (a * 2 - c - d) % mod;
						dp[p + 1][a][nb][c][d] %= mod;
						dp[p + 1][a + 1][nb][c][d] += (long long)s * (a + 1 - c - d) % mod;
						dp[p + 1][a + 1][nb][c][d] %= mod;
						dp[p + 1][a - 1][nb][c][d] += (long long)s * (a - 1) % mod;
						dp[p + 1][a - 1][nb][c][d] %= mod;
						if (c == 0) {
							dp[p + 1][a][nb][1][d] += s;
							dp[p + 1][a][nb][1][d] %= mod;
							dp[p + 1][a + 1][nb][1][d] += s;
							dp[p + 1][a + 1][nb][1][d] %= mod;
						}
						if (d == 0) {
							dp[p + 1][a][nb][c][1] += s;
							dp[p + 1][a][nb][c][1] %= mod;
							dp[p + 1][a + 1][nb][c][1] += s;
							dp[p + 1][a + 1][nb][c][1] %= mod;
						}
					}
				}
			}
		}
	}
	int res = 0;
	for (int b = 0; b <= l; b++) {
		res += dp[n][1][b][1][1];
		res %= mod;
	}
	cout << res;
}

// END MAIN CODE

Compilation message (stderr)

skyscraper.cpp: In function 'void file_io(std::string, std::string)':
skyscraper.cpp:25:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |   freopen(fi.c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:28:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |   freopen(fo.c_str(), "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 80 / 80