#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
/*typedef __uint128_t L;
struct FastMod {
ull b, m;
FastMod(ull b) : b(b), m(ull((L(1) << 64) / b)) {}
ull reduce(ull a) {
ull q = (ull)((L(m) * a) >> 64);
ull r = a - q * b; // can be proven that 0 <= r < 2*b
return r >= b ? r - b : r;
}
};
FastMod FM(2);*/
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
cerr << " " << H;
debug_out(T...);
}
#define debug(...) cerr << "(" << #__VA_ARGS__ << "):", debug_out(__VA_ARGS__)
#define all(x) x.begin(), x.end()
#define MP(x, y) make_pair(x, y)
#define F first
#define S second
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxn = 500 + 10;
const int mod = 1e9 + 7;
int n, dp[maxn][maxn << 1], C[maxn][maxn], CC[maxn << 1][maxn], f[maxn << 1][maxn], inv[maxn], a[maxn], b[maxn];
vector<int> num;
int add(int x, int y){
int res = x + y;
if (res >= mod) return res - mod;
if (res < 0) return res + mod;
return res;
}
int pwr(int a, int b){
int res = 1;
for (; b; b>>=1, a = 1ll * a * a % mod) if (b & 1) res = 1ll * res * a % mod;
return res;
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> n;
for (int i = 1; i <= n; i++){
cin >> a[i] >> b[i];
num.push_back(a[i]);
num.push_back(b[i]+1);
}
num.push_back(0);
sort(all(num));
num.resize(distance(num.begin(), unique(all(num))));
for (int i = 1; i <= n; i++){
inv[i] = pwr(i, mod-2);
}
for (int i = 0; i <= n; i++) C[i][0] = 1;
for (int i = 1; i <= n; i++){
for (int j = 1; j <= n; j++){
C[i][j] = add(C[i-1][j-1], C[i-1][j]);
}
}
for (int i = 0; i + 1 < num.size(); i++){
int tmp = num[i+1] - num[i];
for (int j = 1; j <= n; j++){
if (j > tmp) continue;
CC[i][j] = 1;
for (int k = 1; k <= j; k++){
CC[i][j] = 1ll * CC[i][j] * (tmp - k + 1) % mod * inv[k] % mod;
}
}
}
for (int i = 0; i + 1 < num.size(); i++){
int tmp = num[i+1] - num[i];
for (int j = 1; j <= n; j++){
for (int k = 1; k <= j; k++){
f[i][j] = add(f[i][j], 1ll * CC[i][k] * C[j-1][k-1] % mod);
}
}
}
for (int i = 0; i + 1 < num.size(); i++) dp[0][i] = 1;
for (int i = 1; i <= n; i++){
for (int j = 1; j + 1 < num.size(); j++){
dp[i][j] = dp[i][j-1];
if (a[i] > num[j] || b[i] < num[j]) continue;
int cnt = 1;
for (int k = i-1; ~k; k--){
dp[i][j] = add(dp[i][j], 1ll * dp[k][j-1] * f[j][cnt] % mod);
if (a[k] <= num[j] && num[j] <= b[k]) cnt++;
}
}
}
int ans = 0;
for (int i = 1; i <= n; i++){
ans = add(ans, dp[i][num.size()-2]);
}
cout << ans << '\n';
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:83:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
83 | for (int i = 0; i + 1 < num.size(); i++){
| ~~~~~~^~~~~~~~~~~~
boat.cpp:93:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
93 | for (int i = 0; i + 1 < num.size(); i++){
| ~~~~~~^~~~~~~~~~~~
boat.cpp:94:7: warning: unused variable 'tmp' [-Wunused-variable]
94 | int tmp = num[i+1] - num[i];
| ^~~
boat.cpp:103:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
103 | for (int i = 0; i + 1 < num.size(); i++) dp[0][i] = 1;
| ~~~~~~^~~~~~~~~~~~
boat.cpp:105:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
105 | for (int j = 1; j + 1 < num.size(); j++){
| ~~~~~~^~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1157 ms |
7244 KB |
Output is correct |
2 |
Correct |
1162 ms |
7300 KB |
Output is correct |
3 |
Correct |
1144 ms |
7380 KB |
Output is correct |
4 |
Correct |
1158 ms |
7324 KB |
Output is correct |
5 |
Correct |
1150 ms |
7312 KB |
Output is correct |
6 |
Correct |
1144 ms |
7352 KB |
Output is correct |
7 |
Correct |
1145 ms |
7336 KB |
Output is correct |
8 |
Correct |
1145 ms |
7280 KB |
Output is correct |
9 |
Correct |
1140 ms |
7348 KB |
Output is correct |
10 |
Correct |
1142 ms |
7348 KB |
Output is correct |
11 |
Correct |
1151 ms |
7412 KB |
Output is correct |
12 |
Correct |
1150 ms |
7320 KB |
Output is correct |
13 |
Correct |
1150 ms |
7236 KB |
Output is correct |
14 |
Correct |
1145 ms |
7336 KB |
Output is correct |
15 |
Correct |
1149 ms |
7460 KB |
Output is correct |
16 |
Correct |
206 ms |
3968 KB |
Output is correct |
17 |
Correct |
225 ms |
4048 KB |
Output is correct |
18 |
Correct |
219 ms |
3988 KB |
Output is correct |
19 |
Correct |
221 ms |
4056 KB |
Output is correct |
20 |
Correct |
218 ms |
4032 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1157 ms |
7244 KB |
Output is correct |
2 |
Correct |
1162 ms |
7300 KB |
Output is correct |
3 |
Correct |
1144 ms |
7380 KB |
Output is correct |
4 |
Correct |
1158 ms |
7324 KB |
Output is correct |
5 |
Correct |
1150 ms |
7312 KB |
Output is correct |
6 |
Correct |
1144 ms |
7352 KB |
Output is correct |
7 |
Correct |
1145 ms |
7336 KB |
Output is correct |
8 |
Correct |
1145 ms |
7280 KB |
Output is correct |
9 |
Correct |
1140 ms |
7348 KB |
Output is correct |
10 |
Correct |
1142 ms |
7348 KB |
Output is correct |
11 |
Correct |
1151 ms |
7412 KB |
Output is correct |
12 |
Correct |
1150 ms |
7320 KB |
Output is correct |
13 |
Correct |
1150 ms |
7236 KB |
Output is correct |
14 |
Correct |
1145 ms |
7336 KB |
Output is correct |
15 |
Correct |
1149 ms |
7460 KB |
Output is correct |
16 |
Correct |
206 ms |
3968 KB |
Output is correct |
17 |
Correct |
225 ms |
4048 KB |
Output is correct |
18 |
Correct |
219 ms |
3988 KB |
Output is correct |
19 |
Correct |
221 ms |
4056 KB |
Output is correct |
20 |
Correct |
218 ms |
4032 KB |
Output is correct |
21 |
Correct |
700 ms |
7072 KB |
Output is correct |
22 |
Correct |
676 ms |
6960 KB |
Output is correct |
23 |
Correct |
664 ms |
6964 KB |
Output is correct |
24 |
Correct |
683 ms |
7108 KB |
Output is correct |
25 |
Correct |
740 ms |
6944 KB |
Output is correct |
26 |
Correct |
733 ms |
6800 KB |
Output is correct |
27 |
Correct |
783 ms |
6820 KB |
Output is correct |
28 |
Correct |
742 ms |
6804 KB |
Output is correct |
29 |
Correct |
762 ms |
6724 KB |
Output is correct |
30 |
Correct |
1103 ms |
7324 KB |
Output is correct |
31 |
Correct |
1086 ms |
7256 KB |
Output is correct |
32 |
Correct |
1118 ms |
7224 KB |
Output is correct |
33 |
Correct |
1110 ms |
7248 KB |
Output is correct |
34 |
Correct |
1094 ms |
7264 KB |
Output is correct |
35 |
Correct |
1094 ms |
7332 KB |
Output is correct |
36 |
Correct |
1100 ms |
7268 KB |
Output is correct |
37 |
Correct |
1164 ms |
7272 KB |
Output is correct |
38 |
Correct |
1091 ms |
7372 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
20 ms |
1748 KB |
Output is correct |
2 |
Correct |
20 ms |
1676 KB |
Output is correct |
3 |
Correct |
20 ms |
1732 KB |
Output is correct |
4 |
Correct |
23 ms |
1748 KB |
Output is correct |
5 |
Correct |
21 ms |
1740 KB |
Output is correct |
6 |
Correct |
22 ms |
1672 KB |
Output is correct |
7 |
Correct |
22 ms |
1740 KB |
Output is correct |
8 |
Correct |
21 ms |
1748 KB |
Output is correct |
9 |
Correct |
21 ms |
1652 KB |
Output is correct |
10 |
Correct |
22 ms |
1740 KB |
Output is correct |
11 |
Correct |
21 ms |
1660 KB |
Output is correct |
12 |
Correct |
19 ms |
1736 KB |
Output is correct |
13 |
Correct |
21 ms |
1740 KB |
Output is correct |
14 |
Correct |
23 ms |
1700 KB |
Output is correct |
15 |
Correct |
22 ms |
1748 KB |
Output is correct |
16 |
Correct |
10 ms |
1364 KB |
Output is correct |
17 |
Correct |
10 ms |
1364 KB |
Output is correct |
18 |
Correct |
11 ms |
1364 KB |
Output is correct |
19 |
Correct |
10 ms |
1360 KB |
Output is correct |
20 |
Correct |
11 ms |
1364 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1157 ms |
7244 KB |
Output is correct |
2 |
Correct |
1162 ms |
7300 KB |
Output is correct |
3 |
Correct |
1144 ms |
7380 KB |
Output is correct |
4 |
Correct |
1158 ms |
7324 KB |
Output is correct |
5 |
Correct |
1150 ms |
7312 KB |
Output is correct |
6 |
Correct |
1144 ms |
7352 KB |
Output is correct |
7 |
Correct |
1145 ms |
7336 KB |
Output is correct |
8 |
Correct |
1145 ms |
7280 KB |
Output is correct |
9 |
Correct |
1140 ms |
7348 KB |
Output is correct |
10 |
Correct |
1142 ms |
7348 KB |
Output is correct |
11 |
Correct |
1151 ms |
7412 KB |
Output is correct |
12 |
Correct |
1150 ms |
7320 KB |
Output is correct |
13 |
Correct |
1150 ms |
7236 KB |
Output is correct |
14 |
Correct |
1145 ms |
7336 KB |
Output is correct |
15 |
Correct |
1149 ms |
7460 KB |
Output is correct |
16 |
Correct |
206 ms |
3968 KB |
Output is correct |
17 |
Correct |
225 ms |
4048 KB |
Output is correct |
18 |
Correct |
219 ms |
3988 KB |
Output is correct |
19 |
Correct |
221 ms |
4056 KB |
Output is correct |
20 |
Correct |
218 ms |
4032 KB |
Output is correct |
21 |
Correct |
700 ms |
7072 KB |
Output is correct |
22 |
Correct |
676 ms |
6960 KB |
Output is correct |
23 |
Correct |
664 ms |
6964 KB |
Output is correct |
24 |
Correct |
683 ms |
7108 KB |
Output is correct |
25 |
Correct |
740 ms |
6944 KB |
Output is correct |
26 |
Correct |
733 ms |
6800 KB |
Output is correct |
27 |
Correct |
783 ms |
6820 KB |
Output is correct |
28 |
Correct |
742 ms |
6804 KB |
Output is correct |
29 |
Correct |
762 ms |
6724 KB |
Output is correct |
30 |
Correct |
1103 ms |
7324 KB |
Output is correct |
31 |
Correct |
1086 ms |
7256 KB |
Output is correct |
32 |
Correct |
1118 ms |
7224 KB |
Output is correct |
33 |
Correct |
1110 ms |
7248 KB |
Output is correct |
34 |
Correct |
1094 ms |
7264 KB |
Output is correct |
35 |
Correct |
1094 ms |
7332 KB |
Output is correct |
36 |
Correct |
1100 ms |
7268 KB |
Output is correct |
37 |
Correct |
1164 ms |
7272 KB |
Output is correct |
38 |
Correct |
1091 ms |
7372 KB |
Output is correct |
39 |
Correct |
20 ms |
1748 KB |
Output is correct |
40 |
Correct |
20 ms |
1676 KB |
Output is correct |
41 |
Correct |
20 ms |
1732 KB |
Output is correct |
42 |
Correct |
23 ms |
1748 KB |
Output is correct |
43 |
Correct |
21 ms |
1740 KB |
Output is correct |
44 |
Correct |
22 ms |
1672 KB |
Output is correct |
45 |
Correct |
22 ms |
1740 KB |
Output is correct |
46 |
Correct |
21 ms |
1748 KB |
Output is correct |
47 |
Correct |
21 ms |
1652 KB |
Output is correct |
48 |
Correct |
22 ms |
1740 KB |
Output is correct |
49 |
Correct |
21 ms |
1660 KB |
Output is correct |
50 |
Correct |
19 ms |
1736 KB |
Output is correct |
51 |
Correct |
21 ms |
1740 KB |
Output is correct |
52 |
Correct |
23 ms |
1700 KB |
Output is correct |
53 |
Correct |
22 ms |
1748 KB |
Output is correct |
54 |
Correct |
10 ms |
1364 KB |
Output is correct |
55 |
Correct |
10 ms |
1364 KB |
Output is correct |
56 |
Correct |
11 ms |
1364 KB |
Output is correct |
57 |
Correct |
10 ms |
1360 KB |
Output is correct |
58 |
Correct |
11 ms |
1364 KB |
Output is correct |
59 |
Execution timed out |
2068 ms |
6312 KB |
Time limit exceeded |
60 |
Halted |
0 ms |
0 KB |
- |