#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 500 + 10;
const int mod = 1e9 + 7;
int a[maxn], b[maxn];
int dp[maxn][2*maxn], pd[2*maxn][maxn], c[maxn][maxn];
int revpw[maxn];
int power(int a, int b){
if (b == 0)
return 1;
int ret = power(a,b/2);
ret = 1LL*ret*ret%mod;
if (b & 1)
ret = 1LL*ret*a%mod;
return ret;
}
int main(){
ios_base::sync_with_stdio(false);
int n;
cin >> n;
vector<int> cmp;
for (int i = 1; i <= n; i++){
cin >> a[i] >> b[i];
b[i] ++;
cmp.push_back(a[i]);
cmp.push_back(b[i]);
}
sort(cmp.begin(), cmp.end());
cmp.resize(unique(cmp.begin(),cmp.end())-cmp.begin());
for (int i = 1; i <= n; i++){
a[i] = lower_bound(cmp.begin(),cmp.end(),a[i]) - cmp.begin() + 1;
b[i] = lower_bound(cmp.begin(),cmp.end(),b[i]) - cmp.begin() + 1;
}
c[0][0] = 1;
for (int N = 1; N <= n; N++){
c[N][0] = 1;
for (int R = 1; R <= N; R++)
c[N][R] = (c[N-1][R]+c[N-1][R-1]) % mod;
}
for (int i = 1; i <= 500; i++)
revpw[i] = power(i, mod-2);
for (int i = 1; i < cmp.size(); i++){
int m = cmp[i]-cmp[i-1];
if (m == 1){
pd[i][1] = 1;
continue;
}
pd[i][1] = m;
for (int j = 2; j <= n; j++){
int Cmk = m;
for (int k = 2; k <= min(m,j); k++){
Cmk = 1LL*Cmk*revpw[k]%mod*(m-k+1)%mod;
pd[i][j] = (pd[i][j] + 1LL*c[j-2][k-2]*Cmk) % mod;
}
}
}
dp[0][0] = 1;
for (int i = 0; i < cmp.size(); i++)
dp[0][i] = 1;
for (int i = 1; i <= n; i++){
for (int j = a[i]; j < b[i]; j++){
int cnt = 0;
for (int k = i-1; k >= 0; k--)
if (a[k+1] <= j and j < b[k+1])
dp[i][j] = (dp[i][j] + 1LL*pd[j][++cnt]*dp[k][j-1]) % mod;
}
for (int j = a[i]; j < cmp.size(); j++)
dp[i][j] = (dp[i][j] + dp[i][j-1]) % mod;
for (int j = 0; j < cmp.size(); j++)
dp[i][j] = (dp[i][j] + dp[i-1][j]) % mod;
}
cout << (dp[n][cmp.size()-1]+mod-1) % mod << endl;
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:47:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 1; i < cmp.size(); i++){
~~^~~~~~~~~~~~
boat.cpp:63:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i < cmp.size(); i++)
~~^~~~~~~~~~~~
boat.cpp:72:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int j = a[i]; j < cmp.size(); j++)
~~^~~~~~~~~~~~
boat.cpp:74:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int j = 0; j < cmp.size(); j++)
~~^~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
755 ms |
5384 KB |
Output is correct |
2 |
Correct |
752 ms |
5392 KB |
Output is correct |
3 |
Correct |
765 ms |
5444 KB |
Output is correct |
4 |
Correct |
779 ms |
5368 KB |
Output is correct |
5 |
Correct |
755 ms |
5416 KB |
Output is correct |
6 |
Correct |
741 ms |
5368 KB |
Output is correct |
7 |
Correct |
744 ms |
5556 KB |
Output is correct |
8 |
Correct |
743 ms |
5384 KB |
Output is correct |
9 |
Correct |
774 ms |
5416 KB |
Output is correct |
10 |
Correct |
752 ms |
5368 KB |
Output is correct |
11 |
Correct |
771 ms |
5396 KB |
Output is correct |
12 |
Correct |
778 ms |
5428 KB |
Output is correct |
13 |
Correct |
754 ms |
5372 KB |
Output is correct |
14 |
Correct |
780 ms |
5496 KB |
Output is correct |
15 |
Correct |
779 ms |
5456 KB |
Output is correct |
16 |
Correct |
132 ms |
3756 KB |
Output is correct |
17 |
Correct |
144 ms |
3704 KB |
Output is correct |
18 |
Correct |
139 ms |
3676 KB |
Output is correct |
19 |
Correct |
144 ms |
3704 KB |
Output is correct |
20 |
Correct |
144 ms |
3880 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
755 ms |
5384 KB |
Output is correct |
2 |
Correct |
752 ms |
5392 KB |
Output is correct |
3 |
Correct |
765 ms |
5444 KB |
Output is correct |
4 |
Correct |
779 ms |
5368 KB |
Output is correct |
5 |
Correct |
755 ms |
5416 KB |
Output is correct |
6 |
Correct |
741 ms |
5368 KB |
Output is correct |
7 |
Correct |
744 ms |
5556 KB |
Output is correct |
8 |
Correct |
743 ms |
5384 KB |
Output is correct |
9 |
Correct |
774 ms |
5416 KB |
Output is correct |
10 |
Correct |
752 ms |
5368 KB |
Output is correct |
11 |
Correct |
771 ms |
5396 KB |
Output is correct |
12 |
Correct |
778 ms |
5428 KB |
Output is correct |
13 |
Correct |
754 ms |
5372 KB |
Output is correct |
14 |
Correct |
780 ms |
5496 KB |
Output is correct |
15 |
Correct |
779 ms |
5456 KB |
Output is correct |
16 |
Correct |
132 ms |
3756 KB |
Output is correct |
17 |
Correct |
144 ms |
3704 KB |
Output is correct |
18 |
Correct |
139 ms |
3676 KB |
Output is correct |
19 |
Correct |
144 ms |
3704 KB |
Output is correct |
20 |
Correct |
144 ms |
3880 KB |
Output is correct |
21 |
Correct |
177 ms |
5244 KB |
Output is correct |
22 |
Correct |
175 ms |
5240 KB |
Output is correct |
23 |
Correct |
157 ms |
5112 KB |
Output is correct |
24 |
Correct |
172 ms |
5240 KB |
Output is correct |
25 |
Correct |
183 ms |
5112 KB |
Output is correct |
26 |
Correct |
326 ms |
5112 KB |
Output is correct |
27 |
Correct |
340 ms |
5140 KB |
Output is correct |
28 |
Correct |
330 ms |
5152 KB |
Output is correct |
29 |
Correct |
324 ms |
5244 KB |
Output is correct |
30 |
Correct |
706 ms |
5404 KB |
Output is correct |
31 |
Correct |
706 ms |
5288 KB |
Output is correct |
32 |
Correct |
713 ms |
5496 KB |
Output is correct |
33 |
Correct |
717 ms |
5496 KB |
Output is correct |
34 |
Correct |
716 ms |
5372 KB |
Output is correct |
35 |
Correct |
701 ms |
5412 KB |
Output is correct |
36 |
Correct |
709 ms |
5532 KB |
Output is correct |
37 |
Correct |
724 ms |
5404 KB |
Output is correct |
38 |
Correct |
719 ms |
5484 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
16 ms |
1408 KB |
Output is correct |
2 |
Correct |
17 ms |
1408 KB |
Output is correct |
3 |
Correct |
26 ms |
1408 KB |
Output is correct |
4 |
Correct |
14 ms |
1408 KB |
Output is correct |
5 |
Correct |
15 ms |
1408 KB |
Output is correct |
6 |
Correct |
17 ms |
1408 KB |
Output is correct |
7 |
Correct |
16 ms |
1408 KB |
Output is correct |
8 |
Correct |
16 ms |
1408 KB |
Output is correct |
9 |
Correct |
18 ms |
1408 KB |
Output is correct |
10 |
Correct |
16 ms |
1408 KB |
Output is correct |
11 |
Correct |
15 ms |
1408 KB |
Output is correct |
12 |
Correct |
14 ms |
1408 KB |
Output is correct |
13 |
Correct |
14 ms |
1408 KB |
Output is correct |
14 |
Correct |
14 ms |
1408 KB |
Output is correct |
15 |
Correct |
14 ms |
1408 KB |
Output is correct |
16 |
Correct |
7 ms |
1152 KB |
Output is correct |
17 |
Correct |
8 ms |
1152 KB |
Output is correct |
18 |
Correct |
7 ms |
1152 KB |
Output is correct |
19 |
Correct |
7 ms |
1152 KB |
Output is correct |
20 |
Correct |
7 ms |
1152 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
755 ms |
5384 KB |
Output is correct |
2 |
Correct |
752 ms |
5392 KB |
Output is correct |
3 |
Correct |
765 ms |
5444 KB |
Output is correct |
4 |
Correct |
779 ms |
5368 KB |
Output is correct |
5 |
Correct |
755 ms |
5416 KB |
Output is correct |
6 |
Correct |
741 ms |
5368 KB |
Output is correct |
7 |
Correct |
744 ms |
5556 KB |
Output is correct |
8 |
Correct |
743 ms |
5384 KB |
Output is correct |
9 |
Correct |
774 ms |
5416 KB |
Output is correct |
10 |
Correct |
752 ms |
5368 KB |
Output is correct |
11 |
Correct |
771 ms |
5396 KB |
Output is correct |
12 |
Correct |
778 ms |
5428 KB |
Output is correct |
13 |
Correct |
754 ms |
5372 KB |
Output is correct |
14 |
Correct |
780 ms |
5496 KB |
Output is correct |
15 |
Correct |
779 ms |
5456 KB |
Output is correct |
16 |
Correct |
132 ms |
3756 KB |
Output is correct |
17 |
Correct |
144 ms |
3704 KB |
Output is correct |
18 |
Correct |
139 ms |
3676 KB |
Output is correct |
19 |
Correct |
144 ms |
3704 KB |
Output is correct |
20 |
Correct |
144 ms |
3880 KB |
Output is correct |
21 |
Correct |
177 ms |
5244 KB |
Output is correct |
22 |
Correct |
175 ms |
5240 KB |
Output is correct |
23 |
Correct |
157 ms |
5112 KB |
Output is correct |
24 |
Correct |
172 ms |
5240 KB |
Output is correct |
25 |
Correct |
183 ms |
5112 KB |
Output is correct |
26 |
Correct |
326 ms |
5112 KB |
Output is correct |
27 |
Correct |
340 ms |
5140 KB |
Output is correct |
28 |
Correct |
330 ms |
5152 KB |
Output is correct |
29 |
Correct |
324 ms |
5244 KB |
Output is correct |
30 |
Correct |
706 ms |
5404 KB |
Output is correct |
31 |
Correct |
706 ms |
5288 KB |
Output is correct |
32 |
Correct |
713 ms |
5496 KB |
Output is correct |
33 |
Correct |
717 ms |
5496 KB |
Output is correct |
34 |
Correct |
716 ms |
5372 KB |
Output is correct |
35 |
Correct |
701 ms |
5412 KB |
Output is correct |
36 |
Correct |
709 ms |
5532 KB |
Output is correct |
37 |
Correct |
724 ms |
5404 KB |
Output is correct |
38 |
Correct |
719 ms |
5484 KB |
Output is correct |
39 |
Correct |
16 ms |
1408 KB |
Output is correct |
40 |
Correct |
17 ms |
1408 KB |
Output is correct |
41 |
Correct |
26 ms |
1408 KB |
Output is correct |
42 |
Correct |
14 ms |
1408 KB |
Output is correct |
43 |
Correct |
15 ms |
1408 KB |
Output is correct |
44 |
Correct |
17 ms |
1408 KB |
Output is correct |
45 |
Correct |
16 ms |
1408 KB |
Output is correct |
46 |
Correct |
16 ms |
1408 KB |
Output is correct |
47 |
Correct |
18 ms |
1408 KB |
Output is correct |
48 |
Correct |
16 ms |
1408 KB |
Output is correct |
49 |
Correct |
15 ms |
1408 KB |
Output is correct |
50 |
Correct |
14 ms |
1408 KB |
Output is correct |
51 |
Correct |
14 ms |
1408 KB |
Output is correct |
52 |
Correct |
14 ms |
1408 KB |
Output is correct |
53 |
Correct |
14 ms |
1408 KB |
Output is correct |
54 |
Correct |
7 ms |
1152 KB |
Output is correct |
55 |
Correct |
8 ms |
1152 KB |
Output is correct |
56 |
Correct |
7 ms |
1152 KB |
Output is correct |
57 |
Correct |
7 ms |
1152 KB |
Output is correct |
58 |
Correct |
7 ms |
1152 KB |
Output is correct |
59 |
Correct |
1648 ms |
5496 KB |
Output is correct |
60 |
Correct |
1622 ms |
5496 KB |
Output is correct |
61 |
Correct |
1616 ms |
5416 KB |
Output is correct |
62 |
Correct |
1652 ms |
5624 KB |
Output is correct |
63 |
Correct |
1627 ms |
5420 KB |
Output is correct |
64 |
Correct |
1851 ms |
5448 KB |
Output is correct |
65 |
Correct |
1843 ms |
5540 KB |
Output is correct |
66 |
Correct |
1825 ms |
5464 KB |
Output is correct |
67 |
Correct |
1818 ms |
5520 KB |
Output is correct |
68 |
Correct |
1842 ms |
5432 KB |
Output is correct |
69 |
Correct |
1615 ms |
5644 KB |
Output is correct |
70 |
Correct |
1607 ms |
5416 KB |
Output is correct |
71 |
Correct |
1642 ms |
5380 KB |
Output is correct |
72 |
Correct |
1630 ms |
5384 KB |
Output is correct |
73 |
Correct |
1671 ms |
5388 KB |
Output is correct |
74 |
Correct |
185 ms |
3704 KB |
Output is correct |
75 |
Correct |
203 ms |
3704 KB |
Output is correct |
76 |
Correct |
187 ms |
3704 KB |
Output is correct |
77 |
Correct |
183 ms |
3704 KB |
Output is correct |
78 |
Correct |
185 ms |
3704 KB |
Output is correct |