#include <bits/stdc++.h>
using namespace std;
const int N = 5e2 + 10;
const long long mod = 1e9 + 7;
int n;
long long dp[N][2*N], a[N], b[N];
vector<long long> coord;
long long solve( int pos, long long mi ) {
if( pos > n ){
if( mi == 0 ) return 0;
else return 1;
}
//printf("%d %lld\n",pos,mi);
long long &ret = dp[pos][mi];
if( ret != -1 ) return ret;
ret = 0;
ret = ( ret + solve( pos+1, mi ) ) % mod;
if( mi < a[pos] ) ret = ( ret + solve( pos+1, a[pos] ) ) % mod;
for( int i = max( a[pos] + 1, mi + 1 ) ; i <= b[pos] ; i++ ) ret = ( ret + ( coord[i] - coord[i-1] ) * solve( pos+1, i ) ) % mod;
//printf("%lld\n",ret);
return ret % mod;
}
int main()
{
memset( dp, -1, sizeof dp );
scanf("%d",&n);
coord.emplace_back( 0LL );
for( int i = 1 ; i <= n ; i++ ) {
scanf("%lld %lld",&a[i],&b[i]);
coord.emplace_back( a[i] ), coord.emplace_back( b[i] );
}
sort( coord.begin(), coord.end() );
coord.resize( unique(coord.begin(), coord.end() ) - coord.begin());
for( int i = 1 ; i <= n ; i++ ) {
a[i] = lower_bound( coord.begin(), coord.end(), a[i] ) - coord.begin();
b[i] = lower_bound( coord.begin(), coord.end(), b[i] ) - coord.begin();
}
printf("%lld",solve( 1, 0LL ));
return 0;
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:29:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d",&n);
~~~~~^~~~~~~~~
boat.cpp:32:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%lld %lld",&a[i],&b[i]);
~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 2 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 3 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 4 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 5 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 6 |
Correct |
8 ms |
4472 KB |
Output is correct |
| 7 |
Correct |
10 ms |
4480 KB |
Output is correct |
| 8 |
Correct |
9 ms |
4476 KB |
Output is correct |
| 9 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 10 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 11 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 12 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 13 |
Correct |
9 ms |
4476 KB |
Output is correct |
| 14 |
Correct |
8 ms |
4472 KB |
Output is correct |
| 15 |
Correct |
9 ms |
4452 KB |
Output is correct |
| 16 |
Correct |
8 ms |
4468 KB |
Output is correct |
| 17 |
Correct |
7 ms |
4472 KB |
Output is correct |
| 18 |
Correct |
8 ms |
4472 KB |
Output is correct |
| 19 |
Correct |
8 ms |
4472 KB |
Output is correct |
| 20 |
Correct |
7 ms |
4472 KB |
Output is correct |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 2 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 3 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 4 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 5 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 6 |
Correct |
8 ms |
4472 KB |
Output is correct |
| 7 |
Correct |
10 ms |
4480 KB |
Output is correct |
| 8 |
Correct |
9 ms |
4476 KB |
Output is correct |
| 9 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 10 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 11 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 12 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 13 |
Correct |
9 ms |
4476 KB |
Output is correct |
| 14 |
Correct |
8 ms |
4472 KB |
Output is correct |
| 15 |
Correct |
9 ms |
4452 KB |
Output is correct |
| 16 |
Correct |
8 ms |
4468 KB |
Output is correct |
| 17 |
Correct |
7 ms |
4472 KB |
Output is correct |
| 18 |
Correct |
8 ms |
4472 KB |
Output is correct |
| 19 |
Correct |
8 ms |
4472 KB |
Output is correct |
| 20 |
Correct |
7 ms |
4472 KB |
Output is correct |
| 21 |
Incorrect |
365 ms |
4500 KB |
Output isn't correct |
| 22 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
12 ms |
4344 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 2 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 3 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 4 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 5 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 6 |
Correct |
8 ms |
4472 KB |
Output is correct |
| 7 |
Correct |
10 ms |
4480 KB |
Output is correct |
| 8 |
Correct |
9 ms |
4476 KB |
Output is correct |
| 9 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 10 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 11 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 12 |
Correct |
9 ms |
4472 KB |
Output is correct |
| 13 |
Correct |
9 ms |
4476 KB |
Output is correct |
| 14 |
Correct |
8 ms |
4472 KB |
Output is correct |
| 15 |
Correct |
9 ms |
4452 KB |
Output is correct |
| 16 |
Correct |
8 ms |
4468 KB |
Output is correct |
| 17 |
Correct |
7 ms |
4472 KB |
Output is correct |
| 18 |
Correct |
8 ms |
4472 KB |
Output is correct |
| 19 |
Correct |
8 ms |
4472 KB |
Output is correct |
| 20 |
Correct |
7 ms |
4472 KB |
Output is correct |
| 21 |
Incorrect |
365 ms |
4500 KB |
Output isn't correct |
| 22 |
Halted |
0 ms |
0 KB |
- |
