#include<bits/stdc++.h>
using namespace std;
#define f first
#define s second
typedef long long ll;
const int maxn = 505;
const int mod = 1e9+7;
int n;
pair<int, int> A[maxn];
vector<int> cp;
ll dp[maxn][2*maxn], pc[2*maxn][maxn], inv[2*maxn];
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
inv[0] = inv[1] = 1;
for(int i = 2; i < 2*maxn; i++)inv[i]=mod - inv[mod%i]*(mod/i)%mod;
cin >> n;
for(int i = 1; i <= n; i++){
cin >> A[i].f >> A[i].s;
cp.push_back(A[i].f-1);
cp.push_back(A[i].s);
}
cp.push_back(0);
sort(cp.begin(), cp.end());
cp.erase(unique(cp.begin(), cp.end()), cp.end());
for(int i = 1; i < cp.size(); i++){
ll len = cp[i]-cp[i-1];
pc[i][1] = len;
int bound = 0;
for(int j = 1; j <= n; j++){
if(A[j].s >= cp[i] && A[j].f <= cp[i-1]+1)bound++;
}
for(int j = 2; j <= bound; j++){
ll crr = len*(len-1)/2;
ll sum = 0;
crr%=mod;
for(int k = 2; k <= min(int(len), j); k++){
sum += crr;
// C(k-2, j-2)*C(k, len)
if(sum >= mod)sum-=mod;
crr=crr*(j-k)%mod*inv[k-1]%mod*(len-k)%mod*inv[k+1]%mod;
}
pc[i][j]=sum;
}
}
for(int i = 0; i < cp.size(); i++)dp[0][i]=1;
for(int i = 0; i <= n; i++)dp[i][0]=1;
for(int i = 1; i <= n; i++){
for(int j = 1; j < cp.size(); j++){
if(A[i].f > cp[j] || A[i].s <= cp[j-1])dp[i][j]=0;
else{
int cnt = 0;
for(int k = i; k > 0; k--){
if(A[k].s >= cp[j] && A[k].f <= cp[j-1]+1){
cnt++;
dp[i][j]+=dp[k-1][j-1]*pc[j][cnt]%mod;
if(dp[i][j] >= mod)dp[i][j]-=mod;
if(dp[i][j] < 0)dp[i][j]+=mod;
}
}
}
//cout << i << " " << j << " " << dp[i][j] << endl;
dp[i][j]+=dp[i-1][j]+dp[i][j-1]-dp[i-1][j-1];
dp[i][j]%=mod;
}
}
ll ans = dp[n][cp.size()-1]-1;
ans%=mod;
if(ans < 0)ans+=mod;
cout << ans;
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:35:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
35 | for(int i = 1; i < cp.size(); i++){
| ~~^~~~~~~~~~~
boat.cpp:55:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
55 | for(int i = 0; i < cp.size(); i++)dp[0][i]=1;
| ~~^~~~~~~~~~~
boat.cpp:58:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
58 | for(int j = 1; j < cp.size(); j++){
| ~~^~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
8148 KB |
Output is correct |
2 |
Correct |
8 ms |
8260 KB |
Output is correct |
3 |
Correct |
8 ms |
8148 KB |
Output is correct |
4 |
Correct |
8 ms |
8236 KB |
Output is correct |
5 |
Correct |
9 ms |
8148 KB |
Output is correct |
6 |
Correct |
9 ms |
8356 KB |
Output is correct |
7 |
Correct |
8 ms |
8148 KB |
Output is correct |
8 |
Correct |
7 ms |
8148 KB |
Output is correct |
9 |
Correct |
7 ms |
8188 KB |
Output is correct |
10 |
Correct |
8 ms |
8168 KB |
Output is correct |
11 |
Correct |
8 ms |
8148 KB |
Output is correct |
12 |
Correct |
9 ms |
8176 KB |
Output is correct |
13 |
Correct |
9 ms |
8148 KB |
Output is correct |
14 |
Correct |
8 ms |
8148 KB |
Output is correct |
15 |
Correct |
8 ms |
8148 KB |
Output is correct |
16 |
Correct |
3 ms |
3668 KB |
Output is correct |
17 |
Correct |
3 ms |
3796 KB |
Output is correct |
18 |
Correct |
3 ms |
3668 KB |
Output is correct |
19 |
Correct |
3 ms |
3796 KB |
Output is correct |
20 |
Correct |
3 ms |
3668 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
8148 KB |
Output is correct |
2 |
Correct |
8 ms |
8260 KB |
Output is correct |
3 |
Correct |
8 ms |
8148 KB |
Output is correct |
4 |
Correct |
8 ms |
8236 KB |
Output is correct |
5 |
Correct |
9 ms |
8148 KB |
Output is correct |
6 |
Correct |
9 ms |
8356 KB |
Output is correct |
7 |
Correct |
8 ms |
8148 KB |
Output is correct |
8 |
Correct |
7 ms |
8148 KB |
Output is correct |
9 |
Correct |
7 ms |
8188 KB |
Output is correct |
10 |
Correct |
8 ms |
8168 KB |
Output is correct |
11 |
Correct |
8 ms |
8148 KB |
Output is correct |
12 |
Correct |
9 ms |
8176 KB |
Output is correct |
13 |
Correct |
9 ms |
8148 KB |
Output is correct |
14 |
Correct |
8 ms |
8148 KB |
Output is correct |
15 |
Correct |
8 ms |
8148 KB |
Output is correct |
16 |
Correct |
3 ms |
3668 KB |
Output is correct |
17 |
Correct |
3 ms |
3796 KB |
Output is correct |
18 |
Correct |
3 ms |
3668 KB |
Output is correct |
19 |
Correct |
3 ms |
3796 KB |
Output is correct |
20 |
Correct |
3 ms |
3668 KB |
Output is correct |
21 |
Correct |
288 ms |
7872 KB |
Output is correct |
22 |
Correct |
293 ms |
7936 KB |
Output is correct |
23 |
Correct |
246 ms |
7860 KB |
Output is correct |
24 |
Correct |
279 ms |
7852 KB |
Output is correct |
25 |
Correct |
293 ms |
7884 KB |
Output is correct |
26 |
Correct |
294 ms |
7920 KB |
Output is correct |
27 |
Correct |
316 ms |
7768 KB |
Output is correct |
28 |
Correct |
313 ms |
7656 KB |
Output is correct |
29 |
Correct |
323 ms |
7760 KB |
Output is correct |
30 |
Correct |
8 ms |
8244 KB |
Output is correct |
31 |
Correct |
8 ms |
8176 KB |
Output is correct |
32 |
Correct |
9 ms |
8160 KB |
Output is correct |
33 |
Correct |
8 ms |
8148 KB |
Output is correct |
34 |
Correct |
8 ms |
8148 KB |
Output is correct |
35 |
Correct |
9 ms |
8180 KB |
Output is correct |
36 |
Correct |
9 ms |
8276 KB |
Output is correct |
37 |
Correct |
10 ms |
8168 KB |
Output is correct |
38 |
Correct |
9 ms |
8124 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
1668 KB |
Output is correct |
2 |
Correct |
5 ms |
1620 KB |
Output is correct |
3 |
Correct |
6 ms |
1612 KB |
Output is correct |
4 |
Correct |
6 ms |
1620 KB |
Output is correct |
5 |
Correct |
7 ms |
1620 KB |
Output is correct |
6 |
Correct |
11 ms |
1624 KB |
Output is correct |
7 |
Correct |
11 ms |
1620 KB |
Output is correct |
8 |
Correct |
11 ms |
1628 KB |
Output is correct |
9 |
Correct |
10 ms |
1620 KB |
Output is correct |
10 |
Correct |
10 ms |
1592 KB |
Output is correct |
11 |
Correct |
7 ms |
1620 KB |
Output is correct |
12 |
Correct |
5 ms |
1620 KB |
Output is correct |
13 |
Correct |
5 ms |
1620 KB |
Output is correct |
14 |
Correct |
5 ms |
1620 KB |
Output is correct |
15 |
Correct |
6 ms |
1600 KB |
Output is correct |
16 |
Correct |
3 ms |
1236 KB |
Output is correct |
17 |
Correct |
3 ms |
1236 KB |
Output is correct |
18 |
Correct |
3 ms |
1236 KB |
Output is correct |
19 |
Correct |
2 ms |
1236 KB |
Output is correct |
20 |
Correct |
4 ms |
1236 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
8148 KB |
Output is correct |
2 |
Correct |
8 ms |
8260 KB |
Output is correct |
3 |
Correct |
8 ms |
8148 KB |
Output is correct |
4 |
Correct |
8 ms |
8236 KB |
Output is correct |
5 |
Correct |
9 ms |
8148 KB |
Output is correct |
6 |
Correct |
9 ms |
8356 KB |
Output is correct |
7 |
Correct |
8 ms |
8148 KB |
Output is correct |
8 |
Correct |
7 ms |
8148 KB |
Output is correct |
9 |
Correct |
7 ms |
8188 KB |
Output is correct |
10 |
Correct |
8 ms |
8168 KB |
Output is correct |
11 |
Correct |
8 ms |
8148 KB |
Output is correct |
12 |
Correct |
9 ms |
8176 KB |
Output is correct |
13 |
Correct |
9 ms |
8148 KB |
Output is correct |
14 |
Correct |
8 ms |
8148 KB |
Output is correct |
15 |
Correct |
8 ms |
8148 KB |
Output is correct |
16 |
Correct |
3 ms |
3668 KB |
Output is correct |
17 |
Correct |
3 ms |
3796 KB |
Output is correct |
18 |
Correct |
3 ms |
3668 KB |
Output is correct |
19 |
Correct |
3 ms |
3796 KB |
Output is correct |
20 |
Correct |
3 ms |
3668 KB |
Output is correct |
21 |
Correct |
288 ms |
7872 KB |
Output is correct |
22 |
Correct |
293 ms |
7936 KB |
Output is correct |
23 |
Correct |
246 ms |
7860 KB |
Output is correct |
24 |
Correct |
279 ms |
7852 KB |
Output is correct |
25 |
Correct |
293 ms |
7884 KB |
Output is correct |
26 |
Correct |
294 ms |
7920 KB |
Output is correct |
27 |
Correct |
316 ms |
7768 KB |
Output is correct |
28 |
Correct |
313 ms |
7656 KB |
Output is correct |
29 |
Correct |
323 ms |
7760 KB |
Output is correct |
30 |
Correct |
8 ms |
8244 KB |
Output is correct |
31 |
Correct |
8 ms |
8176 KB |
Output is correct |
32 |
Correct |
9 ms |
8160 KB |
Output is correct |
33 |
Correct |
8 ms |
8148 KB |
Output is correct |
34 |
Correct |
8 ms |
8148 KB |
Output is correct |
35 |
Correct |
9 ms |
8180 KB |
Output is correct |
36 |
Correct |
9 ms |
8276 KB |
Output is correct |
37 |
Correct |
10 ms |
8168 KB |
Output is correct |
38 |
Correct |
9 ms |
8124 KB |
Output is correct |
39 |
Correct |
6 ms |
1668 KB |
Output is correct |
40 |
Correct |
5 ms |
1620 KB |
Output is correct |
41 |
Correct |
6 ms |
1612 KB |
Output is correct |
42 |
Correct |
6 ms |
1620 KB |
Output is correct |
43 |
Correct |
7 ms |
1620 KB |
Output is correct |
44 |
Correct |
11 ms |
1624 KB |
Output is correct |
45 |
Correct |
11 ms |
1620 KB |
Output is correct |
46 |
Correct |
11 ms |
1628 KB |
Output is correct |
47 |
Correct |
10 ms |
1620 KB |
Output is correct |
48 |
Correct |
10 ms |
1592 KB |
Output is correct |
49 |
Correct |
7 ms |
1620 KB |
Output is correct |
50 |
Correct |
5 ms |
1620 KB |
Output is correct |
51 |
Correct |
5 ms |
1620 KB |
Output is correct |
52 |
Correct |
5 ms |
1620 KB |
Output is correct |
53 |
Correct |
6 ms |
1600 KB |
Output is correct |
54 |
Correct |
3 ms |
1236 KB |
Output is correct |
55 |
Correct |
3 ms |
1236 KB |
Output is correct |
56 |
Correct |
3 ms |
1236 KB |
Output is correct |
57 |
Correct |
2 ms |
1236 KB |
Output is correct |
58 |
Correct |
4 ms |
1236 KB |
Output is correct |
59 |
Correct |
657 ms |
8360 KB |
Output is correct |
60 |
Correct |
599 ms |
8248 KB |
Output is correct |
61 |
Correct |
576 ms |
8236 KB |
Output is correct |
62 |
Correct |
684 ms |
8236 KB |
Output is correct |
63 |
Correct |
662 ms |
8180 KB |
Output is correct |
64 |
Correct |
1164 ms |
8136 KB |
Output is correct |
65 |
Correct |
1154 ms |
8204 KB |
Output is correct |
66 |
Correct |
1201 ms |
8240 KB |
Output is correct |
67 |
Correct |
1181 ms |
8164 KB |
Output is correct |
68 |
Correct |
1237 ms |
8136 KB |
Output is correct |
69 |
Correct |
560 ms |
8156 KB |
Output is correct |
70 |
Correct |
542 ms |
8236 KB |
Output is correct |
71 |
Correct |
548 ms |
8172 KB |
Output is correct |
72 |
Correct |
570 ms |
8240 KB |
Output is correct |
73 |
Correct |
563 ms |
8220 KB |
Output is correct |
74 |
Correct |
84 ms |
3744 KB |
Output is correct |
75 |
Correct |
79 ms |
3736 KB |
Output is correct |
76 |
Correct |
78 ms |
3736 KB |
Output is correct |
77 |
Correct |
80 ms |
3692 KB |
Output is correct |
78 |
Correct |
84 ms |
3744 KB |
Output is correct |