#include <bits/stdc++.h>
using namespace std;
string to_string(string s) {
return '"' + s + '"';
}
string to_string(const char* s) {
return to_string((string) s);
}
string to_string(bool b) {
return (b ? "true" : "false");
}
template <typename A, typename B>
string to_string(pair<A, B> p) {
return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A>
string to_string(A v) {
bool first = true;
string res = "{";
for (const auto &x : v) {
if (!first) {
res += ", ";
}
first = false;
res += to_string(x);
}
res += "}";
return res;
}
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
cerr << " " << to_string(H);
debug_out(T...);
}
#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
template <typename T>
T inverse(T a, T m) {
T u = 0, v = 1;
while (a != 0) {
T t = m / a;
m -= t * a; swap(a, m);
u -= t * v; swap(u, v);
}
assert(m == 1);
return u;
}
template <typename T>
class Modular {
public:
using Type = typename decay<decltype(T::value)>::type;
constexpr Modular() : value() {}
template <typename U>
Modular(const U& x) {
value = normalize(x);
}
template <typename U>
static Type normalize(const U& x) {
Type v;
if (-mod() <= x && x < mod()) v = static_cast<Type>(x);
else v = static_cast<Type>(x % mod());
if (v < 0) v += mod();
return v;
}
const Type& operator()() const { return value; }
template <typename U>
explicit operator U() const { return static_cast<U>(value); }
constexpr static Type mod() { return T::value; }
Modular& operator+=(const Modular& other) { if ((value += other.value) >= mod()) value -= mod(); return *this; }
Modular& operator-=(const Modular& other) { if ((value -= other.value) < 0) value += mod(); return *this; }
template <typename U> Modular& operator+=(const U& other) { return *this += Modular(other); }
template <typename U> Modular& operator-=(const U& other) { return *this -= Modular(other); }
Modular& operator++() { return *this += 1; }
Modular& operator--() { return *this -= 1; }
Modular operator++(int) { Modular result(*this); *this += 1; return result; }
Modular operator--(int) { Modular result(*this); *this -= 1; return result; }
Modular operator-() const { return Modular(-value); }
template <typename U = T>
typename enable_if<is_same<typename Modular<U>::Type, int>::value, Modular>::type& operator*=(const Modular& rhs) {
#ifdef _WIN32
uint64_t x = static_cast<int64_t>(value) * static_cast<int64_t>(rhs.value);
uint32_t xh = static_cast<uint32_t>(x >> 32), xl = static_cast<uint32_t>(x), d, m;
asm(
"divl %4; \n\t"
: "=a" (d), "=d" (m)
: "d" (xh), "a" (xl), "r" (mod())
);
value = m;
#else
value = normalize(static_cast<int64_t>(value) * static_cast<int64_t>(rhs.value));
#endif
return *this;
}
template <typename U = T>
typename enable_if<is_same<typename Modular<U>::Type, int64_t>::value, Modular>::type& operator*=(const Modular& rhs) {
int64_t q = static_cast<int64_t>(static_cast<long double>(value) * rhs.value / mod());
value = normalize(value * rhs.value - q * mod());
return *this;
}
template <typename U = T>
typename enable_if<!is_integral<typename Modular<U>::Type>::value, Modular>::type& operator*=(const Modular& rhs) {
value = normalize(value * rhs.value);
return *this;
}
Modular& operator/=(const Modular& other) { return *this *= Modular(inverse(other.value, mod())); }
template <typename U>
friend bool operator==(const Modular<U>& lhs, const Modular<U>& rhs);
template <typename U>
friend bool operator<(const Modular<U>& lhs, const Modular<U>& rhs);
template <typename U>
friend std::istream& operator>>(std::istream& stream, Modular<U>& number);
private:
Type value;
};
template <typename T> bool operator==(const Modular<T>& lhs, const Modular<T>& rhs) { return lhs.value == rhs.value; }
template <typename T, typename U> bool operator==(const Modular<T>& lhs, U rhs) { return lhs == Modular<T>(rhs); }
template <typename T, typename U> bool operator==(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) == rhs; }
template <typename T> bool operator!=(const Modular<T>& lhs, const Modular<T>& rhs) { return !(lhs == rhs); }
template <typename T, typename U> bool operator!=(const Modular<T>& lhs, U rhs) { return !(lhs == rhs); }
template <typename T, typename U> bool operator!=(U lhs, const Modular<T>& rhs) { return !(lhs == rhs); }
template <typename T> bool operator<(const Modular<T>& lhs, const Modular<T>& rhs) { return lhs.value < rhs.value; }
template <typename T> Modular<T> operator+(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) += rhs; }
template <typename T, typename U> Modular<T> operator+(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) += rhs; }
template <typename T, typename U> Modular<T> operator+(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) += rhs; }
template <typename T> Modular<T> operator-(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T, typename U> Modular<T> operator-(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T, typename U> Modular<T> operator-(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T> Modular<T> operator*(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T, typename U> Modular<T> operator*(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T, typename U> Modular<T> operator*(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T> Modular<T> operator/(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) /= rhs; }
template <typename T, typename U> Modular<T> operator/(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) /= rhs; }
template <typename T, typename U> Modular<T> operator/(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) /= rhs; }
template<typename T, typename U>
Modular<T> power(const Modular<T>& a, const U& b) {
assert(b >= 0);
Modular<T> x = a, res = 1;
U p = b;
while (p > 0) {
if (p & 1) res *= x;
x *= x;
p >>= 1;
}
return res;
}
template <typename T>
string to_string(const Modular<T>& number) {
return to_string(number());
}
template <typename T>
std::ostream& operator<<(std::ostream& stream, const Modular<T>& number) {
return stream << number();
}
template <typename T>
std::istream& operator>>(std::istream& stream, Modular<T>& number) {
typename common_type<typename Modular<T>::Type, int64_t>::type x;
stream >> x;
number.value = Modular<T>::normalize(x);
return stream;
}
/*
using ModType = int;
struct VarMod { static ModType value; };
ModType VarMod::value;
ModType& md = VarMod::value;
using Mint = Modular<VarMod>;
*/
constexpr int md = 1e9 + 7;
using Mint = Modular<std::integral_constant<decay<decltype(md)>::type, md>>;
vector<Mint> fact(1, 1);
vector<Mint> inv_fact(1, 1);
Mint C(int n, int k) {
if (k < 0 || k > n) {
return 0;
}
while ((int) fact.size() < n + 1) {
fact.push_back(fact.back() * (int) fact.size());
inv_fact.push_back(1 / fact.back());
}
return fact[n] * inv_fact[k] * inv_fact[n - k];
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
vector<int> a(n), b(n);
for (int i = 0; i < n; i++) {
cin >> a[i] >> b[i];
}
vector<int> xs;
for (int i = 0; i < n; i++) {
xs.push_back(a[i]);
xs.push_back(b[i] + 1);
}
sort(xs.begin(), xs.end());
xs.erase(unique(xs.begin(), xs.end()), xs.end());
int m = xs.size();
vector<vector<Mint>> f(n + 1, vector<Mint>(m + 1));
f[0][0] = 1;
for (int i = 0; i < n; i++) {
vector<Mint> new_f(m);
new_f[0] = f[i][0];
for (int j = 1; j < m; j++) {
new_f[j] = new_f[j - 1] + f[i][j];
}
for (int j = 0; j < m; j++) {
f[i + 1][j] += f[i][j];
}
for (int j = 0; j < m; j++) {
int L = xs[j];
int R = (j == m - 1 ? 1e9 + 5 : xs[j + 1] - 1);
for (int p = i; p < n; p++) {
if (a[p] > L || b[p] < R) {
break;
}
f[p + 1][j + 1] += new_f[j] * C(R - L + 1, p - i + 1);
}
}
}
debug(f);
Mint ans = 0;
for (int i = 0; i < m; i++) {
ans += f[n][i];
}
cout << ans - 1 << '\n';
return 0;
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:41:20: warning: statement has no effect [-Wunused-value]
41 | #define debug(...) 42
| ^~
boat.cpp:231:3: note: in expansion of macro 'debug'
231 | debug(f);
| ^~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
2260 KB |
Output is correct |
2 |
Correct |
6 ms |
2260 KB |
Output is correct |
3 |
Correct |
6 ms |
2260 KB |
Output is correct |
4 |
Correct |
6 ms |
2260 KB |
Output is correct |
5 |
Correct |
6 ms |
2260 KB |
Output is correct |
6 |
Correct |
6 ms |
2248 KB |
Output is correct |
7 |
Correct |
6 ms |
2260 KB |
Output is correct |
8 |
Correct |
5 ms |
2248 KB |
Output is correct |
9 |
Correct |
6 ms |
2260 KB |
Output is correct |
10 |
Correct |
6 ms |
2260 KB |
Output is correct |
11 |
Correct |
5 ms |
2244 KB |
Output is correct |
12 |
Correct |
6 ms |
2260 KB |
Output is correct |
13 |
Correct |
6 ms |
2324 KB |
Output is correct |
14 |
Correct |
7 ms |
2260 KB |
Output is correct |
15 |
Correct |
6 ms |
2260 KB |
Output is correct |
16 |
Correct |
2 ms |
596 KB |
Output is correct |
17 |
Correct |
2 ms |
724 KB |
Output is correct |
18 |
Correct |
2 ms |
724 KB |
Output is correct |
19 |
Correct |
2 ms |
724 KB |
Output is correct |
20 |
Correct |
2 ms |
596 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
2260 KB |
Output is correct |
2 |
Correct |
6 ms |
2260 KB |
Output is correct |
3 |
Correct |
6 ms |
2260 KB |
Output is correct |
4 |
Correct |
6 ms |
2260 KB |
Output is correct |
5 |
Correct |
6 ms |
2260 KB |
Output is correct |
6 |
Correct |
6 ms |
2248 KB |
Output is correct |
7 |
Correct |
6 ms |
2260 KB |
Output is correct |
8 |
Correct |
5 ms |
2248 KB |
Output is correct |
9 |
Correct |
6 ms |
2260 KB |
Output is correct |
10 |
Correct |
6 ms |
2260 KB |
Output is correct |
11 |
Correct |
5 ms |
2244 KB |
Output is correct |
12 |
Correct |
6 ms |
2260 KB |
Output is correct |
13 |
Correct |
6 ms |
2324 KB |
Output is correct |
14 |
Correct |
7 ms |
2260 KB |
Output is correct |
15 |
Correct |
6 ms |
2260 KB |
Output is correct |
16 |
Correct |
2 ms |
596 KB |
Output is correct |
17 |
Correct |
2 ms |
724 KB |
Output is correct |
18 |
Correct |
2 ms |
724 KB |
Output is correct |
19 |
Correct |
2 ms |
724 KB |
Output is correct |
20 |
Correct |
2 ms |
596 KB |
Output is correct |
21 |
Incorrect |
10 ms |
2116 KB |
Output isn't correct |
22 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Execution timed out |
2092 ms |
197684 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
2260 KB |
Output is correct |
2 |
Correct |
6 ms |
2260 KB |
Output is correct |
3 |
Correct |
6 ms |
2260 KB |
Output is correct |
4 |
Correct |
6 ms |
2260 KB |
Output is correct |
5 |
Correct |
6 ms |
2260 KB |
Output is correct |
6 |
Correct |
6 ms |
2248 KB |
Output is correct |
7 |
Correct |
6 ms |
2260 KB |
Output is correct |
8 |
Correct |
5 ms |
2248 KB |
Output is correct |
9 |
Correct |
6 ms |
2260 KB |
Output is correct |
10 |
Correct |
6 ms |
2260 KB |
Output is correct |
11 |
Correct |
5 ms |
2244 KB |
Output is correct |
12 |
Correct |
6 ms |
2260 KB |
Output is correct |
13 |
Correct |
6 ms |
2324 KB |
Output is correct |
14 |
Correct |
7 ms |
2260 KB |
Output is correct |
15 |
Correct |
6 ms |
2260 KB |
Output is correct |
16 |
Correct |
2 ms |
596 KB |
Output is correct |
17 |
Correct |
2 ms |
724 KB |
Output is correct |
18 |
Correct |
2 ms |
724 KB |
Output is correct |
19 |
Correct |
2 ms |
724 KB |
Output is correct |
20 |
Correct |
2 ms |
596 KB |
Output is correct |
21 |
Incorrect |
10 ms |
2116 KB |
Output isn't correct |
22 |
Halted |
0 ms |
0 KB |
- |