oj.uz

Submission #40748

# Submission time Handle Problem Language Result Execution time Memory
40748 2018-02-08T02:41:38 Z ssnsarang2023 Boat (APIO16_boat) C++14
36 / 100
 101 ms 2668 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> ii;

#define SZ(x) ((int)x.size())

const int mod = (int)1e9+7;

int fast_pw(int a, int b) {
	int res = 1;
	while (b) {
		if (b & 1) res = 1ll * res * a % mod; 
		a = 1ll * a * a % mod;
		b >>= 1;
	}
	return res;
}

const int N = 505;
int n, f[N], g[N], ftmp[N], a[N], b[N], inv[N], tmp[N], m;
int choose[N][N], len[N], lenCk[N][N], c1[N];
vector<int> c;

void add(int &x, int y) {
	x += y, x %= mod;
	if (x < 0) x += mod;
}

int main() {
	scanf("%d", &n);
	for (int i = 1; i <= n; ++i) {
		scanf("%d%d", &a[i], &b[i]);
		++b[i];
		c.push_back(a[i]);
		c.push_back(b[i]);
	}
	sort(c.begin(), c.end());
	c.resize(distance(c.begin(), unique(c.begin(), c.end())));
	for (int i = 0; i <= n; ++i) choose[i][i] = choose[i][0] = 1;
	inv[0] = f[0] = g[0] = 1;
	for (int i = 1; i <= n; ++i) {
		for (int j = 1; j < i; ++j)
			choose[i][j] = (choose[i - 1][j - 1] + choose[i - 1][j]) % mod;
		inv[i] = fast_pw(i, mod - 2);
		g[i] = 1;
	}
	int sz = 0;
	for (int i = 0; i < SZ(c) - 1; ++i) {
		len[++sz] = c[i + 1] - c[i];
		lenCk[sz][0] = 1;
		for (int j = 1; j <= min(len[sz], n); ++j) {
			lenCk[sz][j] = 1ll * lenCk[sz][j - 1] * (len[sz] - j + 1) % mod;
			lenCk[sz][j] = 1ll * lenCk[sz][j] * inv[j] % mod;
		}
	}
	for (int i = 1; i <= sz; ++i) {
		m = 0;
		for (int j = 1; j <= n; ++j)
			if (a[j] <= c[i - 1] && c[i] <= b[j])
				tmp[++m] = j;
		for (int j = 1; j <= m; ++j) {
			int id = tmp[j];
			if (j == 1) {
				for (int k = 0; k <= m; ++k) c1[k] = 0;
				c1[1] = lenCk[i][1];
				for (int k = 2; k <= m; ++k)
					for (int x = 2; x <= min(k, len[i]); ++x)
						add(c1[k], 1ll * lenCk[i][x] * choose[k - 2][x - 2] % mod);
			}
			for (int k = j; k <= m; ++k) {
				int mid = k - j + 1, id2 = tmp[k];
				add(ftmp[id2], 1ll * c1[mid] * g[id - 1] % mod);
			}
		}
		g[0] = 1;
		for (int j = 1; j <= n; ++j) {
			add(f[j], ftmp[j]);
			g[j] = (g[j - 1] + f[j]) % mod;
			ftmp[j] = 0;
		}
	}
	printf("%d", (g[n] - 1 + mod) % mod);
	return 0;
}

Compilation message

boat.cpp: In function 'int main()':
boat.cpp:34:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
boat.cpp:36:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &a[i], &b[i]);
                              ^

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 2296 KB Output is correct
2 Correct 11 ms 2400 KB Output is correct
3 Correct 12 ms 2400 KB Output is correct
4 Correct 11 ms 2400 KB Output is correct
5 Correct 12 ms 2596 KB Output is correct
6 Correct 11 ms 2596 KB Output is correct
7 Correct 10 ms 2664 KB Output is correct
8 Correct 10 ms 2664 KB Output is correct
9 Correct 10 ms 2668 KB Output is correct
10 Correct 10 ms 2668 KB Output is correct
11 Correct 10 ms 2668 KB Output is correct
12 Correct 10 ms 2668 KB Output is correct
13 Correct 10 ms 2668 KB Output is correct
14 Correct 11 ms 2668 KB Output is correct
15 Correct 10 ms 2668 KB Output is correct
16 Correct 4 ms 2668 KB Output is correct
17 Correct 4 ms 2668 KB Output is correct
18 Correct 4 ms 2668 KB Output is correct
19 Correct 4 ms 2668 KB Output is correct
20 Correct 4 ms 2668 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 2296 KB Output is correct
2 Correct 11 ms 2400 KB Output is correct
3 Correct 12 ms 2400 KB Output is correct
4 Correct 11 ms 2400 KB Output is correct
5 Correct 12 ms 2596 KB Output is correct
6 Correct 11 ms 2596 KB Output is correct
7 Correct 10 ms 2664 KB Output is correct
8 Correct 10 ms 2664 KB Output is correct
9 Correct 10 ms 2668 KB Output is correct
10 Correct 10 ms 2668 KB Output is correct
11 Correct 10 ms 2668 KB Output is correct
12 Correct 10 ms 2668 KB Output is correct
13 Correct 10 ms 2668 KB Output is correct
14 Correct 11 ms 2668 KB Output is correct
15 Correct 10 ms 2668 KB Output is correct
16 Correct 4 ms 2668 KB Output is correct
17 Correct 4 ms 2668 KB Output is correct
18 Correct 4 ms 2668 KB Output is correct
19 Correct 4 ms 2668 KB Output is correct
20 Correct 4 ms 2668 KB Output is correct
21 Incorrect 101 ms 2668 KB Output isn't correct
22 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 2668 KB Output is correct
2 Correct 3 ms 2668 KB Output is correct
3 Correct 4 ms 2668 KB Output is correct
4 Correct 4 ms 2668 KB Output is correct
5 Correct 4 ms 2668 KB Output is correct
6 Correct 6 ms 2668 KB Output is correct
7 Correct 7 ms 2668 KB Output is correct
8 Correct 7 ms 2668 KB Output is correct
9 Correct 6 ms 2668 KB Output is correct
10 Correct 6 ms 2668 KB Output is correct
11 Correct 5 ms 2668 KB Output is correct
12 Correct 3 ms 2668 KB Output is correct
13 Correct 4 ms 2668 KB Output is correct
14 Correct 4 ms 2668 KB Output is correct
15 Correct 4 ms 2668 KB Output is correct
16 Correct 3 ms 2668 KB Output is correct
17 Correct 3 ms 2668 KB Output is correct
18 Correct 3 ms 2668 KB Output is correct
19 Correct 3 ms 2668 KB Output is correct
20 Correct 3 ms 2668 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 2296 KB Output is correct
2 Correct 11 ms 2400 KB Output is correct
3 Correct 12 ms 2400 KB Output is correct
4 Correct 11 ms 2400 KB Output is correct
5 Correct 12 ms 2596 KB Output is correct
6 Correct 11 ms 2596 KB Output is correct
7 Correct 10 ms 2664 KB Output is correct
8 Correct 10 ms 2664 KB Output is correct
9 Correct 10 ms 2668 KB Output is correct
10 Correct 10 ms 2668 KB Output is correct
11 Correct 10 ms 2668 KB Output is correct
12 Correct 10 ms 2668 KB Output is correct
13 Correct 10 ms 2668 KB Output is correct
14 Correct 11 ms 2668 KB Output is correct
15 Correct 10 ms 2668 KB Output is correct
16 Correct 4 ms 2668 KB Output is correct
17 Correct 4 ms 2668 KB Output is correct
18 Correct 4 ms 2668 KB Output is correct
19 Correct 4 ms 2668 KB Output is correct
20 Correct 4 ms 2668 KB Output is correct
21 Incorrect 101 ms 2668 KB Output isn't correct
22 Halted 0 ms 0 KB -