#include<iostream>
#include<cstring>
#include<vector>
#include<algorithm>
using namespace std;
int n,a[505],b[505],dp[1505][2][505][2],inv[505],mod=1e9+7;
vector <int> v,v1;
vector <vector<int> > v2;
int sum(int a,int b) {
return (a+b)%mod;
}
int mul(int a,int b) {
return ((long long)a*b)%mod;
}
int exp(int a,int b) {
if(!b) return 1;
int ret=exp(a,b/2);
if(b%2==0) return mul(ret,ret);
return mul(mul(ret,ret),a);
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> n;
for(int i=0;i<n;i++) {
cin >> a[i] >> b[i];
v.push_back(a[i]);
v.push_back(b[i]);
v.push_back(b[i]+1);
}
sort(v.begin(),v.end());
v.erase(unique(v.begin(),v.end()),v.end());
/*for(int i=0;i<v.size()-1;i++) {
cout << v[i] << " " << v[i+1]-1 << "\n";
}*/
/*for(int i=0;i<n;i++) {
a[i]=lower_bound(v.begin(),v.end(),a[i])-v.begin();
b[i]=lower_bound(v.begin(),v.end(),b[i])-v.begin();
}*/
for(int i=1;i<=n;i++) {
inv[i]=exp(i,mod-2);
}
for(int i=0;i<v.size()-1;i++) {
for(int j=0;j<=n;j++) {
dp[i][n%2][j][0]=1;
dp[i][n%2][j][1]=1;
}
}
for(int x=n-1;x>=0;x--) {
for(int idx=v.size()-2;idx>=0;idx--) {
for(int cnt=0;cnt<=x;cnt++) {
for(int a1=0;a1<2;a1++) {
int ret=0;
if(!a1) ret=sum(ret,dp[idx][(x+1)%2][cnt][0]); // 0
if(v[idx]>=a[x] && v[idx+1]-1<=b[x]) {
if(cnt<=v[idx+1]-1-v[idx]) ret=sum(ret,mul(dp[idx][(x+1)%2][cnt+1][0],mul(v[idx+1]-v[idx]-cnt,inv[cnt+1])));
}
ret=sum(ret,dp[idx+1][x%2][0][1]);
dp[idx][x%2][cnt][a1]=ret;
//cout << idx << " " << x << " " << cnt << " " << a1 << " " << ret << "\n";
}
}
}
}
cout << dp[0][0][0][0]-1;
return 0;
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:44:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
44 | for(int i=0;i<v.size()-1;i++) {
| ~^~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1611 ms |
8228 KB |
Output is correct |
2 |
Correct |
1622 ms |
8256 KB |
Output is correct |
3 |
Correct |
1612 ms |
8240 KB |
Output is correct |
4 |
Correct |
1615 ms |
8244 KB |
Output is correct |
5 |
Correct |
1612 ms |
8244 KB |
Output is correct |
6 |
Correct |
1616 ms |
8240 KB |
Output is correct |
7 |
Correct |
1617 ms |
8268 KB |
Output is correct |
8 |
Correct |
1619 ms |
8268 KB |
Output is correct |
9 |
Correct |
1622 ms |
8268 KB |
Output is correct |
10 |
Correct |
1612 ms |
8252 KB |
Output is correct |
11 |
Correct |
1611 ms |
8240 KB |
Output is correct |
12 |
Correct |
1615 ms |
8244 KB |
Output is correct |
13 |
Correct |
1617 ms |
8240 KB |
Output is correct |
14 |
Correct |
1610 ms |
8252 KB |
Output is correct |
15 |
Correct |
1613 ms |
8240 KB |
Output is correct |
16 |
Correct |
283 ms |
1748 KB |
Output is correct |
17 |
Correct |
306 ms |
1840 KB |
Output is correct |
18 |
Correct |
293 ms |
1780 KB |
Output is correct |
19 |
Correct |
306 ms |
1852 KB |
Output is correct |
20 |
Correct |
297 ms |
1792 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1611 ms |
8228 KB |
Output is correct |
2 |
Correct |
1622 ms |
8256 KB |
Output is correct |
3 |
Correct |
1612 ms |
8240 KB |
Output is correct |
4 |
Correct |
1615 ms |
8244 KB |
Output is correct |
5 |
Correct |
1612 ms |
8244 KB |
Output is correct |
6 |
Correct |
1616 ms |
8240 KB |
Output is correct |
7 |
Correct |
1617 ms |
8268 KB |
Output is correct |
8 |
Correct |
1619 ms |
8268 KB |
Output is correct |
9 |
Correct |
1622 ms |
8268 KB |
Output is correct |
10 |
Correct |
1612 ms |
8252 KB |
Output is correct |
11 |
Correct |
1611 ms |
8240 KB |
Output is correct |
12 |
Correct |
1615 ms |
8244 KB |
Output is correct |
13 |
Correct |
1617 ms |
8240 KB |
Output is correct |
14 |
Correct |
1610 ms |
8252 KB |
Output is correct |
15 |
Correct |
1613 ms |
8240 KB |
Output is correct |
16 |
Correct |
283 ms |
1748 KB |
Output is correct |
17 |
Correct |
306 ms |
1840 KB |
Output is correct |
18 |
Correct |
293 ms |
1780 KB |
Output is correct |
19 |
Correct |
306 ms |
1852 KB |
Output is correct |
20 |
Correct |
297 ms |
1792 KB |
Output is correct |
21 |
Execution timed out |
2078 ms |
10580 KB |
Time limit exceeded |
22 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
33 ms |
2644 KB |
Output is correct |
2 |
Correct |
33 ms |
2644 KB |
Output is correct |
3 |
Correct |
33 ms |
2644 KB |
Output is correct |
4 |
Correct |
34 ms |
2644 KB |
Output is correct |
5 |
Correct |
35 ms |
2644 KB |
Output is correct |
6 |
Correct |
40 ms |
2644 KB |
Output is correct |
7 |
Correct |
41 ms |
2644 KB |
Output is correct |
8 |
Correct |
40 ms |
2644 KB |
Output is correct |
9 |
Correct |
41 ms |
2644 KB |
Output is correct |
10 |
Correct |
40 ms |
2668 KB |
Output is correct |
11 |
Correct |
32 ms |
2644 KB |
Output is correct |
12 |
Correct |
30 ms |
2644 KB |
Output is correct |
13 |
Correct |
30 ms |
2696 KB |
Output is correct |
14 |
Correct |
31 ms |
2684 KB |
Output is correct |
15 |
Correct |
32 ms |
2644 KB |
Output is correct |
16 |
Correct |
16 ms |
1488 KB |
Output is correct |
17 |
Correct |
15 ms |
1448 KB |
Output is correct |
18 |
Correct |
15 ms |
1448 KB |
Output is correct |
19 |
Correct |
15 ms |
1428 KB |
Output is correct |
20 |
Correct |
17 ms |
1364 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1611 ms |
8228 KB |
Output is correct |
2 |
Correct |
1622 ms |
8256 KB |
Output is correct |
3 |
Correct |
1612 ms |
8240 KB |
Output is correct |
4 |
Correct |
1615 ms |
8244 KB |
Output is correct |
5 |
Correct |
1612 ms |
8244 KB |
Output is correct |
6 |
Correct |
1616 ms |
8240 KB |
Output is correct |
7 |
Correct |
1617 ms |
8268 KB |
Output is correct |
8 |
Correct |
1619 ms |
8268 KB |
Output is correct |
9 |
Correct |
1622 ms |
8268 KB |
Output is correct |
10 |
Correct |
1612 ms |
8252 KB |
Output is correct |
11 |
Correct |
1611 ms |
8240 KB |
Output is correct |
12 |
Correct |
1615 ms |
8244 KB |
Output is correct |
13 |
Correct |
1617 ms |
8240 KB |
Output is correct |
14 |
Correct |
1610 ms |
8252 KB |
Output is correct |
15 |
Correct |
1613 ms |
8240 KB |
Output is correct |
16 |
Correct |
283 ms |
1748 KB |
Output is correct |
17 |
Correct |
306 ms |
1840 KB |
Output is correct |
18 |
Correct |
293 ms |
1780 KB |
Output is correct |
19 |
Correct |
306 ms |
1852 KB |
Output is correct |
20 |
Correct |
297 ms |
1792 KB |
Output is correct |
21 |
Execution timed out |
2078 ms |
10580 KB |
Time limit exceeded |
22 |
Halted |
0 ms |
0 KB |
- |