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Submission #545822

# Submission time Handle Problem Language Result Execution time Memory
545822 2022-04-05T14:05:04 Z Sohsoh84 Boat (APIO16_boat) C++17
0 / 100
 13 ms 10356 KB 
#include <bits/stdc++.h>

using namespace std;


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

#define int			ll
#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) {
	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();
}

int32_t main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> L[i] >> R[i];
		vec.push_back(L[i]);
		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] < L[i] && R[i] <= vec[j]);
		
		PC[j][0] = C[j][0] = 1;
		int sz = vec[j] - vec[j - 1];
		for (int i = 1; i <= min(sz, n); i++) {
			C[j][i] = 1ll * C[j][i - 1] * (sz - i + 1) % MOD * inv[i] % MOD; 	
			mkey(PC[j][i] = PC[j][i - 1] + C[j][i]);
		}
	}


	fill(dp[0], dp[0] + MAXN, 1);
	int ans = 0;
	for (int i = 1; i <= n; i++) {
		int l = ind(L[i]), r = ind(R[i]);
		for (int j = 1; j < int(vec.size()); j++) {
			int sz = vec[j] - vec[j - 1];
			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][min(sz, ps[j][i - 1] - 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 Correct 11 ms 10324 KB Output is correct
2 Correct 11 ms 10324 KB Output is correct
3 Correct 13 ms 10300 KB Output is correct
4 Correct 12 ms 10356 KB Output is correct
5 Correct 12 ms 10324 KB Output is correct
6 Correct 11 ms 10220 KB Output is correct
7 Correct 10 ms 10324 KB Output is correct
8 Correct 10 ms 10324 KB Output is correct
9 Correct 11 ms 10324 KB Output is correct
10 Correct 11 ms 10324 KB Output is correct
11 Correct 10 ms 10324 KB Output is correct
12 Correct 10 ms 10260 KB Output is correct
13 Correct 10 ms 10324 KB Output is correct
14 Correct 10 ms 10324 KB Output is correct
15 Correct 11 ms 10232 KB Output is correct
16 Incorrect 4 ms 3796 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 10324 KB Output is correct
2 Correct 11 ms 10324 KB Output is correct
3 Correct 13 ms 10300 KB Output is correct
4 Correct 12 ms 10356 KB Output is correct
5 Correct 12 ms 10324 KB Output is correct
6 Correct 11 ms 10220 KB Output is correct
7 Correct 10 ms 10324 KB Output is correct
8 Correct 10 ms 10324 KB Output is correct
9 Correct 11 ms 10324 KB Output is correct
10 Correct 11 ms 10324 KB Output is correct
11 Correct 10 ms 10324 KB Output is correct
12 Correct 10 ms 10260 KB Output is correct
13 Correct 10 ms 10324 KB Output is correct
14 Correct 10 ms 10324 KB Output is correct
15 Correct 11 ms 10232 KB Output is correct
16 Incorrect 4 ms 3796 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 3284 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 10324 KB Output is correct
2 Correct 11 ms 10324 KB Output is correct
3 Correct 13 ms 10300 KB Output is correct
4 Correct 12 ms 10356 KB Output is correct
5 Correct 12 ms 10324 KB Output is correct
6 Correct 11 ms 10220 KB Output is correct
7 Correct 10 ms 10324 KB Output is correct
8 Correct 10 ms 10324 KB Output is correct
9 Correct 11 ms 10324 KB Output is correct
10 Correct 11 ms 10324 KB Output is correct
11 Correct 10 ms 10324 KB Output is correct
12 Correct 10 ms 10260 KB Output is correct
13 Correct 10 ms 10324 KB Output is correct
14 Correct 10 ms 10324 KB Output is correct
15 Correct 11 ms 10232 KB Output is correct
16 Incorrect 4 ms 3796 KB Output isn't correct
17 Halted 0 ms 0 KB -