제출 #376291

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
376291		shivensinha4	Boat (APIO16_boat)	C++17	58 / 100	2082 ms	16364 KiB

boat

#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#include "bits/stdc++.h"
using namespace std;
#define for_(i, s, e) for (int i = s; i < (int) e; i++)
#define for__(i, s, e) for (ll i = s; i < e; i++)
typedef long long ll;
typedef vector<int> vi;
typedef array<int, 2> ii;
// #define endl '\n'

namespace speedy_io {
	int read_nonneg() {
		int c;
		while ((c = getchar_unlocked()) < '0' || c > '9');
		int v = c - '0';
		while ((c = getchar_unlocked()) >= '0' && c <= '9') {
			v = (v << 3) + (v << 1) + (c - '0');
		}
		return v;
	}
	
	const int max_ll_size = 20;
	void put_nonneg(ll n) {
		int i = max_ll_size;
		char output_buffer[max_ll_size];
		do {
			output_buffer[--i] = (n % 10) + '0';
			n /= 10;
		} while (n);
		do {
			putchar_unlocked(output_buffer[i]);
		} while (++i < max_ll_size);
	}
}

using namespace speedy_io;

 
const ll mod = 1e9+7;
 
ll power(ll x, ll y) {
	if (y == 0) return 1;
	ll p = power(x, y/2) % mod;
	p = (p * p) % mod;
  
	return (y%2 == 0)? p : (x * p) % mod;
}
 
ll modInverse(ll a) {
	return power(a, mod-2);
}
 
const int MXN = 500;
ll choose[4*MXN+2][MXN+1], dp[2][MXN+1][MXN+1][2];
 
int main() {
#ifdef mlocal
	freopen("test.in", "r", stdin);
#endif
	
	// ios_base::sync_with_stdio(false);
	// cin.tie(0);
	
	int n = read_nonneg();
	vector<ii> lt(n);
	vi raw(2*n);
	
	for_(i, 0, n) {
		lt[i][0] = read_nonneg(), lt[i][1] = read_nonneg();
		lt[i][1]++;
		raw[2*i] = lt[i][0], raw[2*i+1] = lt[i][1];
	}
	
	sort(raw.begin(), raw.end());
	raw.resize(unique(raw.begin(), raw.end()) - raw.begin());
	
	vector<ii> seg;
	// int pre = -1;
	for_(i, 1, raw.size()) {
		// if (pre < raw[i] and pre != -1) seg.push_back({pre, raw[i]-1});
		seg.push_back({raw[i-1], raw[i]-1});
		// pre = raw[i]+1;
	}
	
	int ns = seg.size();
	// cout << ns << endl;
	// for (auto i: seg) cout << i[0] << " " << i[1] << endl;
	memset(choose, 0, sizeof(choose)); memset(dp, 0, sizeof(dp));
	
	vector<ll> modInv(n+1);
	for_(i, 1, n+1) modInv[i] = modInverse(i);
	
	for_(i, 0, ns) {
		choose[i][0] = 1;
		for_(r, 1, min(n, seg[i][1]-seg[i][0]+1) + 1) choose[i][r] = (((choose[i][r-1] * (seg[i][1]-seg[i][0]-r+2)) % mod) * modInv[r]) % mod;
	}
	
	bool valid[n];
	
	int c = 0;
	for (int s = ns-1; s >= 0; s--) {
		memset(dp[c], 0, sizeof(dp[c]));
		
		for_(idx, 0, n) valid[idx] = seg[s][0] >= lt[idx][0] and seg[s][1] < lt[idx][1];
		
		for (int ct = min(n-1, seg[s][1]-seg[s][0]+1); ct >= 0; ct--) {
			dp[c][ct][n][0] = choose[s][ct];
			
			for (int idx = n-1; idx >= 0; idx--) {
				if (valid[idx]) dp[c][ct][idx][1] += dp[c][ct+1][idx+1][0];
				if (dp[c][ct][idx][1] >= mod) dp[c][ct][idx][1] -= mod;
				
				dp[c][ct][idx][1] += (choose[s][ct] * (s < ns-1 ? dp[1-c][0][idx][1] : 0)) % mod;
				if (dp[c][ct][idx][1] >= mod) dp[c][ct][idx][1] -= mod;
				
				dp[c][ct][idx][0] = dp[c][ct][idx][1] + dp[c][ct][idx+1][0];
				if (dp[c][ct][idx][0] >= mod) dp[c][ct][idx][0] -= mod;
			}
		}
		c = 1-c;
	}
	
	put_nonneg((dp[1-c][0][0][0]-1+mod) % mod);
	printf("\n");
	
}

• Subtask 1: 9 / 9
• Subtask 2: 22 / 22
• Subtask 3: 27 / 27
• Subtask 4: 0 / 42