oj.uz

Submission #545848

# Submission time Handle Problem Language Result Execution time Memory
545848 2022-04-05T15:12:16 Z Sohsoh84 Boat (APIO16_boat) C++17
27 / 100
 657 ms 6492 KB 
#include <bits/stdc++.h>

using namespace std;


typedef long long ll;
typedef pair<ll, ll> pll;

#define all(x)			(x).begin(),(x).end()
#define X			first
#define Y			second
#define sep			' '
#define endl			'\n'
#define debug(x)		cerr << #x << ": " <<  x << endl;

const ll MAXN = 500 + 10;
const ll MOD = 1e9 + 7;

void mkey(int& a) {
	if (a >= MOD) a -= MOD;
}

inline ll poww(ll a, ll b) {
	ll ans = 1;
	while (b) {
		if (b & 1) ans = ans * a % MOD;
		b >>= 1;
		a = a * a % MOD;
	}

	return ans;
}

int n, L[MAXN], R[MAXN], C[MAXN][MAXN], PC[MAXN][MAXN], dp[MAXN][MAXN * 2], 
    ps[2 * MAXN][MAXN], inv[MAXN];
vector<int> vec;

inline int ind(int x) {
	return lower_bound(all(vec), x) - vec.begin();
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);	
	C[0][0] = 1;
	for (int i = 1; i < MAXN; i++) {
		C[i][0] = 1;
		for (int j = 1; j <= i; j++)
			mkey(C[i][j] = C[i - 1][j - 1] + C[i - 1][j]);
	}

	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> L[i] >> R[i];
		vec.push_back(L[i] - 1);
		vec.push_back(R[i]);
		inv[i] = poww(i, MOD - 2);
	}

	vec.push_back(-1);
	sort(all(vec));
	vec.resize(unique(all(vec)) - vec.begin());

	for (int j = 1; j < int(vec.size()); j++) {
		for (int i = 1; i <= n; i++) {
			ps[j][i] = ps[j][i - 1] + (vec[j - 1] + 1 >= L[i] && vec[j] <= R[i]);
		}

		int sz = vec[j] - vec[j - 1];
		for (int k = 1; k <= n; k++) {	
			ll f = 1;
			for (int i = 1; i <= min(sz, k); i++) {
				f = f * (sz - i + 1) % MOD * inv[i] % MOD;
				mkey(PC[j][k] += f * C[k - 1][i - 1] % MOD);
			}
		}
	}


	fill(dp[0], dp[0] + MAXN, 1);
	int ans = 0;
	for (int i = 1; i <= n; i++) {
		int l = ind(L[i] - 1), r = ind(R[i]);
		for (int j = 1; j < int(vec.size()); j++) {
			dp[i][j] = dp[i][j - 1];
			
			if (j > l && j <= r) {
				for (int k = 0; k < i; k++) {
					dp[i][j] = (dp[i][j] + 1ll * PC[j][ps[j][i] - ps[j][k]] * dp[k][j - 1]) % MOD;	
				}
			}
		}

		mkey(ans += dp[i][int(vec.size()) - 1]);
	}

	cout << ans << endl;
	return 0;
}

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Incorrect 657 ms 6492 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 657 ms 6492 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 2516 KB Output is correct
2 Correct 15 ms 2508 KB Output is correct
3 Correct 14 ms 2516 KB Output is correct
4 Correct 15 ms 2472 KB Output is correct
5 Correct 15 ms 2500 KB Output is correct
6 Correct 15 ms 2520 KB Output is correct
7 Correct 16 ms 2448 KB Output is correct
8 Correct 17 ms 2444 KB Output is correct
9 Correct 15 ms 2516 KB Output is correct
10 Correct 17 ms 2440 KB Output is correct
11 Correct 18 ms 2528 KB Output is correct
12 Correct 16 ms 2452 KB Output is correct
13 Correct 14 ms 2496 KB Output is correct
14 Correct 15 ms 2516 KB Output is correct
15 Correct 15 ms 2508 KB Output is correct
16 Correct 7 ms 2132 KB Output is correct
17 Correct 7 ms 2132 KB Output is correct
18 Correct 7 ms 2132 KB Output is correct
19 Correct 7 ms 2120 KB Output is correct
20 Correct 8 ms 2132 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Incorrect 657 ms 6492 KB Output isn't correct
2 Halted 0 ms 0 KB -