#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int md = (int)1e9 + 7;
int pw(int x, int y) {
int res = 1;
while (y) {
if (y & 1) res = (ll)res * x % md;
x = (ll)x * x % md; y >>= 1;
}
return res;
}
int C(int n, int r) {
int x = 1, y = 1;
for (int i = 1; i <= r; i++) {
x = (ll)x * (n - r + i) % md;
y = (ll)y * i % md;
}
return (ll)x * pw(y, md - 2) % md;
}
int main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
int n;
cin >> n;
map<int, vector<int>> m;
vector<int> a(n + 1), b(n + 1);
for (int i = 1; i <= n; i++) {
cin >> a[i] >> b[i];
m[a[i]].push_back(i);
m[b[i] + 1].push_back(-i);
}
vector<int> mv;
for (auto i : m) mv.push_back(i.first);
set<int> s;
vector<int> dp(n + 1);
for (int ii = 0; ii + 1 < (int)mv.size(); ii++) {
for (auto j : m[mv[ii]]) {
if (0 < j) s.insert(j);
else s.erase(-j);
}
int R = mv[ii + 1] - mv[ii];
vector<int> v(s.begin(), s.end()), nw_dp = dp;
for (int i = 0; i < (int)v.size(); i++) {
int sm = 1;
for (int j = 1; j < v[i]; j++) sm = (sm + dp[j]) % md;
nw_dp[v[i]] = (dp[v[i]] + (ll)sm * R % md) % md;
for (int j = 1; j <= min(i, R - 1); j++) {
int c = C(R, j + 1), sm = 1;
for (int k = 1; k <= v[i - j]; k++) sm = (sm + dp[k]) % md;
for (int k = i - j; k >= 0; k--) {
int sm = 1;
for (int l = 1; l < v[k]; l++) sm = (sm + dp[l]) % md;
nw_dp[v[i]] = (nw_dp[v[i]] + ((ll)sm * C(i - k - 1, j - 1) % md) * c % md) % md;
}
}
}
dp = nw_dp;
}
int sm = 0;
for (auto i : dp) sm = (sm + i) % md;
cout << sm << '\n';
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
344 KB |
Output is correct |
7 |
Correct |
1 ms |
348 KB |
Output is correct |
8 |
Correct |
1 ms |
348 KB |
Output is correct |
9 |
Correct |
1 ms |
344 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
11 |
Correct |
1 ms |
348 KB |
Output is correct |
12 |
Correct |
1 ms |
348 KB |
Output is correct |
13 |
Correct |
1 ms |
348 KB |
Output is correct |
14 |
Correct |
1 ms |
348 KB |
Output is correct |
15 |
Correct |
1 ms |
464 KB |
Output is correct |
16 |
Correct |
1 ms |
348 KB |
Output is correct |
17 |
Correct |
1 ms |
348 KB |
Output is correct |
18 |
Correct |
1 ms |
344 KB |
Output is correct |
19 |
Correct |
1 ms |
348 KB |
Output is correct |
20 |
Correct |
1 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
344 KB |
Output is correct |
7 |
Correct |
1 ms |
348 KB |
Output is correct |
8 |
Correct |
1 ms |
348 KB |
Output is correct |
9 |
Correct |
1 ms |
344 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
11 |
Correct |
1 ms |
348 KB |
Output is correct |
12 |
Correct |
1 ms |
348 KB |
Output is correct |
13 |
Correct |
1 ms |
348 KB |
Output is correct |
14 |
Correct |
1 ms |
348 KB |
Output is correct |
15 |
Correct |
1 ms |
464 KB |
Output is correct |
16 |
Correct |
1 ms |
348 KB |
Output is correct |
17 |
Correct |
1 ms |
348 KB |
Output is correct |
18 |
Correct |
1 ms |
344 KB |
Output is correct |
19 |
Correct |
1 ms |
348 KB |
Output is correct |
20 |
Correct |
1 ms |
348 KB |
Output is correct |
21 |
Execution timed out |
2056 ms |
556 KB |
Time limit exceeded |
22 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
563 ms |
592 KB |
Output is correct |
2 |
Correct |
318 ms |
344 KB |
Output is correct |
3 |
Correct |
491 ms |
456 KB |
Output is correct |
4 |
Correct |
570 ms |
464 KB |
Output is correct |
5 |
Correct |
701 ms |
344 KB |
Output is correct |
6 |
Execution timed out |
2025 ms |
344 KB |
Time limit exceeded |
7 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
348 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
344 KB |
Output is correct |
7 |
Correct |
1 ms |
348 KB |
Output is correct |
8 |
Correct |
1 ms |
348 KB |
Output is correct |
9 |
Correct |
1 ms |
344 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
11 |
Correct |
1 ms |
348 KB |
Output is correct |
12 |
Correct |
1 ms |
348 KB |
Output is correct |
13 |
Correct |
1 ms |
348 KB |
Output is correct |
14 |
Correct |
1 ms |
348 KB |
Output is correct |
15 |
Correct |
1 ms |
464 KB |
Output is correct |
16 |
Correct |
1 ms |
348 KB |
Output is correct |
17 |
Correct |
1 ms |
348 KB |
Output is correct |
18 |
Correct |
1 ms |
344 KB |
Output is correct |
19 |
Correct |
1 ms |
348 KB |
Output is correct |
20 |
Correct |
1 ms |
348 KB |
Output is correct |
21 |
Execution timed out |
2056 ms |
556 KB |
Time limit exceeded |
22 |
Halted |
0 ms |
0 KB |
- |