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Submission #48616

# Submission time Handle Problem Language Result Execution time Memory
48616 2018-05-17T11:34:49 Z nobik Boat (APIO16_boat) C++14
27 / 100
 1860 ms 2420 KB 
#include <bits/stdc++.h>
using namespace std;

#define REP(i, n) for (int i = 0; i < (n); ++i)
#define SIZE(a) ((int)(a).size())
#define ALL(a) (a).begin(), (a).end()

using ll = long long;
using K = long double;

const int inf = 1000*1000*1000 + 7;
const int mod = 1000*1000*1000 + 7;
const int N = 505;

int power(int a, int n) {
	int result = 1;
	while (n > 0) {
		if (n % 2) {
			result = (1LL*result*a) % mod;
		}
		a = (1LL*a*a) % mod;
		n /= 2;
	}
	return result;
}

int inv(int a) {
	return power(a, mod-2);
}

void add(int &x, int y) {
	x += y;
	if (x >= mod) x -= mod;
}

int n, m, l[N], r[N];
vector<int> d;
int f[N][N], g[N][N];

int inside(int id, int piece) {
	return l[id] <= d[piece] && r[id] >= d[piece+1];
}

int iv[N];

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	cin >> n;
	REP(i, n) {
		cin >> l[i] >> r[i];
		++r[i];
		d.push_back(l[i]);
		d.push_back(r[i]);
	}
	sort(d.begin(), d.end());
	d.erase(unique(d.begin(), d.end()), d.end());
	m = SIZE(d)-1;
	f[0][0] = 1;
	for (int i = 1; i <= n; ++i) {
		iv[i] = inv(i);
	}
	for (int i = 0; i <= n; ++i) REP(w, m) {
		int len = d[w+1]-d[w];
		int first = len;
		int second = 1;
		for (int j = 0; j <= i; ++j) {
			first = 1LL*first*(len-j-1) % mod;
			first = 1LL*first*iv[j+2] % mod;
			add(g[i][w], 1LL*first*second % mod);
			second = 1LL*second*(i-j) % mod;
			second = 1LL*second*iv[j+1] % mod;
		}
	}
	REP(i, n) {
		REP(j, m+1) add(f[i+1][j], f[i][j]);
		REP(j, m) {
			add(f[i][j+1], f[i][j]);
			if (!inside(i, j)) continue;
			add(f[i+1][j+1], 1LL*f[i][j]*(d[j+1]-d[j]) % mod);
			int cnt = -1;
			for (int nxt = i+1; nxt < n; ++nxt) {
				if (!inside(nxt, j)) continue;
				++cnt;
				add(f[nxt+1][j+1], 1LL*f[i][j]*g[cnt][j] % mod);
			}
		}
	}
	int result = mod-1;
	REP(i, m+1) add(result, f[n][i]);
	cout << result << '\n';
}

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Incorrect 1860 ms 2420 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 1860 ms 2420 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 21 ms 2420 KB Output is correct
2 Correct 19 ms 2420 KB Output is correct
3 Correct 20 ms 2420 KB Output is correct
4 Correct 19 ms 2420 KB Output is correct
5 Correct 20 ms 2420 KB Output is correct
6 Correct 21 ms 2420 KB Output is correct
7 Correct 25 ms 2420 KB Output is correct
8 Correct 21 ms 2420 KB Output is correct
9 Correct 20 ms 2420 KB Output is correct
10 Correct 20 ms 2420 KB Output is correct
11 Correct 20 ms 2420 KB Output is correct
12 Correct 29 ms 2420 KB Output is correct
13 Correct 19 ms 2420 KB Output is correct
14 Correct 19 ms 2420 KB Output is correct
15 Correct 19 ms 2420 KB Output is correct
16 Correct 12 ms 2420 KB Output is correct
17 Correct 12 ms 2420 KB Output is correct
18 Correct 12 ms 2420 KB Output is correct
19 Correct 12 ms 2420 KB Output is correct
20 Correct 12 ms 2420 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Incorrect 1860 ms 2420 KB Output isn't correct
2 Halted 0 ms 0 KB -