#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int mxN=500, M=1e9+7;
int n, a[mxN], b[mxN];
ll dp[mxN+1][2*mxN], c[2*mxN][mxN+1];
vector<int> pts;
inline ll modI(ll a, ll m) {
return a<=1?a:(1-modI(m%a, a)*m)/a+m;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
// cout << modI(2, M) << endl;
cin >> n;
for(int i=0; i<n; ++i) {
cin >> a[i] >> b[i], --a[i];
pts.push_back(a[i]);
pts.push_back(b[i]);
}
sort(pts.begin(), pts.end());
pts.resize(unique(pts.begin(), pts.end())-pts.begin());
for(int i=1; i<pts.size(); ++i) {
c[i][1]=pts[i]-pts[i-1];
for(int j=2; j<=n; ++j)
c[i][j]=c[i][j-1]*(pts[i]-pts[i-1]+j-1)%M*modI(j, M)%M;
}
for(int i=0; i<pts.size(); ++i)
dp[0][i]=1;
for(int i=1; i<=n; ++i) {
dp[i][0]=1;
for(int j=1; j<pts.size(); ++j) {
dp[i][j]=dp[i][j-1];
for(int k=i, n2=0; k; --k) {
if(pts[j]>a[k-1]&&pts[j]<=b[k-1]) {
++n2;
dp[i][j]+=dp[k-1][j-1]*c[j][n2]%M;//, cout << c[j][i-k] << " ";
}
}
// cout << endl;
dp[i][j]%=M;
// cout << i << " " << j << " " << dp[i][j] << endl;
}
}
cout << dp[n][pts.size()-1]-1;
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:28:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=1; i<pts.size(); ++i) {
~^~~~~~~~~~~
boat.cpp:33:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0; i<pts.size(); ++i)
~^~~~~~~~~~~
boat.cpp:37:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=1; j<pts.size(); ++j) {
~^~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
495 ms |
8312 KB |
Output is correct |
| 2 |
Correct |
494 ms |
8312 KB |
Output is correct |
| 3 |
Correct |
499 ms |
8372 KB |
Output is correct |
| 4 |
Correct |
514 ms |
8372 KB |
Output is correct |
| 5 |
Correct |
519 ms |
8544 KB |
Output is correct |
| 6 |
Correct |
255 ms |
8544 KB |
Output is correct |
| 7 |
Correct |
251 ms |
8668 KB |
Output is correct |
| 8 |
Correct |
259 ms |
8668 KB |
Output is correct |
| 9 |
Correct |
263 ms |
8668 KB |
Output is correct |
| 10 |
Correct |
252 ms |
8780 KB |
Output is correct |
| 11 |
Correct |
256 ms |
8848 KB |
Output is correct |
| 12 |
Correct |
263 ms |
8848 KB |
Output is correct |
| 13 |
Correct |
260 ms |
8848 KB |
Output is correct |
| 14 |
Correct |
269 ms |
8880 KB |
Output is correct |
| 15 |
Correct |
262 ms |
8880 KB |
Output is correct |
| 16 |
Correct |
94 ms |
8880 KB |
Output is correct |
| 17 |
Correct |
99 ms |
8880 KB |
Output is correct |
| 18 |
Correct |
100 ms |
8880 KB |
Output is correct |
| 19 |
Correct |
101 ms |
8880 KB |
Output is correct |
| 20 |
Correct |
98 ms |
8880 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
495 ms |
8312 KB |
Output is correct |
| 2 |
Correct |
494 ms |
8312 KB |
Output is correct |
| 3 |
Correct |
499 ms |
8372 KB |
Output is correct |
| 4 |
Correct |
514 ms |
8372 KB |
Output is correct |
| 5 |
Correct |
519 ms |
8544 KB |
Output is correct |
| 6 |
Correct |
255 ms |
8544 KB |
Output is correct |
| 7 |
Correct |
251 ms |
8668 KB |
Output is correct |
| 8 |
Correct |
259 ms |
8668 KB |
Output is correct |
| 9 |
Correct |
263 ms |
8668 KB |
Output is correct |
| 10 |
Correct |
252 ms |
8780 KB |
Output is correct |
| 11 |
Correct |
256 ms |
8848 KB |
Output is correct |
| 12 |
Correct |
263 ms |
8848 KB |
Output is correct |
| 13 |
Correct |
260 ms |
8848 KB |
Output is correct |
| 14 |
Correct |
269 ms |
8880 KB |
Output is correct |
| 15 |
Correct |
262 ms |
8880 KB |
Output is correct |
| 16 |
Correct |
94 ms |
8880 KB |
Output is correct |
| 17 |
Correct |
99 ms |
8880 KB |
Output is correct |
| 18 |
Correct |
100 ms |
8880 KB |
Output is correct |
| 19 |
Correct |
101 ms |
8880 KB |
Output is correct |
| 20 |
Correct |
98 ms |
8880 KB |
Output is correct |
| 21 |
Correct |
391 ms |
8880 KB |
Output is correct |
| 22 |
Correct |
401 ms |
8880 KB |
Output is correct |
| 23 |
Correct |
450 ms |
8880 KB |
Output is correct |
| 24 |
Correct |
434 ms |
8880 KB |
Output is correct |
| 25 |
Correct |
401 ms |
8880 KB |
Output is correct |
| 26 |
Correct |
437 ms |
8880 KB |
Output is correct |
| 27 |
Correct |
447 ms |
8880 KB |
Output is correct |
| 28 |
Correct |
448 ms |
8880 KB |
Output is correct |
| 29 |
Correct |
384 ms |
8880 KB |
Output is correct |
| 30 |
Correct |
312 ms |
9068 KB |
Output is correct |
| 31 |
Correct |
249 ms |
9068 KB |
Output is correct |
| 32 |
Correct |
256 ms |
9068 KB |
Output is correct |
| 33 |
Correct |
253 ms |
9080 KB |
Output is correct |
| 34 |
Correct |
248 ms |
9096 KB |
Output is correct |
| 35 |
Correct |
514 ms |
9168 KB |
Output is correct |
| 36 |
Correct |
492 ms |
9168 KB |
Output is correct |
| 37 |
Correct |
488 ms |
9168 KB |
Output is correct |
| 38 |
Correct |
502 ms |
9168 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 2 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 3 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 4 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 5 |
Correct |
8 ms |
9168 KB |
Output is correct |
| 6 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 7 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 8 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 9 |
Correct |
8 ms |
9168 KB |
Output is correct |
| 10 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 11 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 12 |
Correct |
8 ms |
9168 KB |
Output is correct |
| 13 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 14 |
Correct |
8 ms |
9168 KB |
Output is correct |
| 15 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 16 |
Correct |
7 ms |
9168 KB |
Output is correct |
| 17 |
Correct |
6 ms |
9168 KB |
Output is correct |
| 18 |
Correct |
7 ms |
9168 KB |
Output is correct |
| 19 |
Correct |
6 ms |
9168 KB |
Output is correct |
| 20 |
Correct |
6 ms |
9168 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
495 ms |
8312 KB |
Output is correct |
| 2 |
Correct |
494 ms |
8312 KB |
Output is correct |
| 3 |
Correct |
499 ms |
8372 KB |
Output is correct |
| 4 |
Correct |
514 ms |
8372 KB |
Output is correct |
| 5 |
Correct |
519 ms |
8544 KB |
Output is correct |
| 6 |
Correct |
255 ms |
8544 KB |
Output is correct |
| 7 |
Correct |
251 ms |
8668 KB |
Output is correct |
| 8 |
Correct |
259 ms |
8668 KB |
Output is correct |
| 9 |
Correct |
263 ms |
8668 KB |
Output is correct |
| 10 |
Correct |
252 ms |
8780 KB |
Output is correct |
| 11 |
Correct |
256 ms |
8848 KB |
Output is correct |
| 12 |
Correct |
263 ms |
8848 KB |
Output is correct |
| 13 |
Correct |
260 ms |
8848 KB |
Output is correct |
| 14 |
Correct |
269 ms |
8880 KB |
Output is correct |
| 15 |
Correct |
262 ms |
8880 KB |
Output is correct |
| 16 |
Correct |
94 ms |
8880 KB |
Output is correct |
| 17 |
Correct |
99 ms |
8880 KB |
Output is correct |
| 18 |
Correct |
100 ms |
8880 KB |
Output is correct |
| 19 |
Correct |
101 ms |
8880 KB |
Output is correct |
| 20 |
Correct |
98 ms |
8880 KB |
Output is correct |
| 21 |
Correct |
391 ms |
8880 KB |
Output is correct |
| 22 |
Correct |
401 ms |
8880 KB |
Output is correct |
| 23 |
Correct |
450 ms |
8880 KB |
Output is correct |
| 24 |
Correct |
434 ms |
8880 KB |
Output is correct |
| 25 |
Correct |
401 ms |
8880 KB |
Output is correct |
| 26 |
Correct |
437 ms |
8880 KB |
Output is correct |
| 27 |
Correct |
447 ms |
8880 KB |
Output is correct |
| 28 |
Correct |
448 ms |
8880 KB |
Output is correct |
| 29 |
Correct |
384 ms |
8880 KB |
Output is correct |
| 30 |
Correct |
312 ms |
9068 KB |
Output is correct |
| 31 |
Correct |
249 ms |
9068 KB |
Output is correct |
| 32 |
Correct |
256 ms |
9068 KB |
Output is correct |
| 33 |
Correct |
253 ms |
9080 KB |
Output is correct |
| 34 |
Correct |
248 ms |
9096 KB |
Output is correct |
| 35 |
Correct |
514 ms |
9168 KB |
Output is correct |
| 36 |
Correct |
492 ms |
9168 KB |
Output is correct |
| 37 |
Correct |
488 ms |
9168 KB |
Output is correct |
| 38 |
Correct |
502 ms |
9168 KB |
Output is correct |
| 39 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 40 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 41 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 42 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 43 |
Correct |
8 ms |
9168 KB |
Output is correct |
| 44 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 45 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 46 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 47 |
Correct |
8 ms |
9168 KB |
Output is correct |
| 48 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 49 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 50 |
Correct |
8 ms |
9168 KB |
Output is correct |
| 51 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 52 |
Correct |
8 ms |
9168 KB |
Output is correct |
| 53 |
Correct |
9 ms |
9168 KB |
Output is correct |
| 54 |
Correct |
7 ms |
9168 KB |
Output is correct |
| 55 |
Correct |
6 ms |
9168 KB |
Output is correct |
| 56 |
Correct |
7 ms |
9168 KB |
Output is correct |
| 57 |
Correct |
6 ms |
9168 KB |
Output is correct |
| 58 |
Correct |
6 ms |
9168 KB |
Output is correct |
| 59 |
Correct |
481 ms |
9168 KB |
Output is correct |
| 60 |
Correct |
478 ms |
9248 KB |
Output is correct |
| 61 |
Correct |
455 ms |
9288 KB |
Output is correct |
| 62 |
Correct |
429 ms |
9288 KB |
Output is correct |
| 63 |
Correct |
426 ms |
9288 KB |
Output is correct |
| 64 |
Correct |
448 ms |
9296 KB |
Output is correct |
| 65 |
Correct |
440 ms |
9296 KB |
Output is correct |
| 66 |
Correct |
442 ms |
9320 KB |
Output is correct |
| 67 |
Correct |
424 ms |
9320 KB |
Output is correct |
| 68 |
Correct |
503 ms |
9344 KB |
Output is correct |
| 69 |
Correct |
558 ms |
9344 KB |
Output is correct |
| 70 |
Correct |
523 ms |
9376 KB |
Output is correct |
| 71 |
Correct |
460 ms |
9376 KB |
Output is correct |
| 72 |
Correct |
442 ms |
9392 KB |
Output is correct |
| 73 |
Correct |
606 ms |
9404 KB |
Output is correct |
| 74 |
Correct |
119 ms |
9404 KB |
Output is correct |
| 75 |
Correct |
131 ms |
9404 KB |
Output is correct |
| 76 |
Correct |
121 ms |
9404 KB |
Output is correct |
| 77 |
Correct |
116 ms |
9404 KB |
Output is correct |
| 78 |
Correct |
109 ms |
9404 KB |
Output is correct |
