#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <set>
#include <map>
#include <time.h>
using namespace std;
long long MOD=1e9+7;
long long DP[505][2005];
bool use[505][2005]={0};
long long cha[2005],Con[2005],R[2005];
map < long long , long long > all;
long long N,now=0;
long long a[505],b[505];
map < long long , long long > con,r;
set < long long > have;
long long Pow(long long a,long long b)
{
if(b==0) return a;
long long t=Pow(a,b/2);
t*=t;
t%=MOD;
if(b%2) t*=a;
return t%MOD;
}
long long F(long long x,long long y)
{
long long i,j,tt;
if(x==0) return y!=(now);
if(use[x][y]) return DP[x][y];
use[x][y]=1;
DP[x][y]=F(x-1,y);
for(i=0;i<now;i++)
{
//printf("aa %lld %lld %lld %lld %lld\n",x,y,i,cha[i],a[x]);
if(cha[i]>=a[x]&&R[i]<cha[y]&&R[i]<=b[x])
{
tt=1;
for(j=x;j>=1;j--)
{
if(cha[i]>=a[j]&&R[i]<cha[y]&&R[i]<=b[j])
{
tt*=(Con[i]-(x-j));
tt%=MOD;
tt*=Pow(x-j+1,MOD-2);
tt%=MOD;
DP[x][y]+=tt*F(j-1,i)%MOD;
DP[x][y]%=MOD;
}
else break;
}
}
}
//printf("%lld %lld %lld\n",x,y,DP[x][y]);
return DP[x][y];
}
int main()
{
//freopen("3_01.in","rt",stdin);
//srand(time(NULL));
long long N,M,i;
scanf("%lld",&N);
for(i=1;i<=N;i++)
{
scanf("%lld %lld",&a[i],&b[i]);
have.insert(a[i]);
have.insert(a[i]+1);
have.insert(b[i]);
have.insert(b[i]+1);
}
for(auto i:have)
{
if(i==*prev(have.end()))
{
con[i]=1;
r[i]=i;
}
if(have.lower_bound(i)!=have.begin())
{
con[*prev(have.lower_bound(i))]=i-*prev(have.lower_bound(i));
r[*prev(have.lower_bound(i))]=i-1;
}
}
for(auto i:con)
{
cha[now]=i.first;
Con[now]=i.second;
R[now]=r[i.first];
now++;
}
cha[now]=1e9+5;
Con[now]=0;
R[now]=2e9;
//for(i=0;i<now;i++) printf("aa %lld %lld %lld %lld\n",i,cha[i],Con[i],R[i]);
printf("%lld\n",F(N,now));
return 0;
}
/*
2
32 47
18 78
*/
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:67:17: warning: unused variable 'M' [-Wunused-variable]
long long N,M,i;
^
boat.cpp:68:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%lld",&N);
~~~~~^~~~~~~~~~~
boat.cpp:71:14: 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 |
179 ms |
7416 KB |
Output is correct |
2 |
Correct |
178 ms |
7416 KB |
Output is correct |
3 |
Correct |
186 ms |
7416 KB |
Output is correct |
4 |
Correct |
178 ms |
7416 KB |
Output is correct |
5 |
Correct |
178 ms |
7416 KB |
Output is correct |
6 |
Correct |
221 ms |
6392 KB |
Output is correct |
7 |
Correct |
222 ms |
6136 KB |
Output is correct |
8 |
Correct |
221 ms |
6776 KB |
Output is correct |
9 |
Correct |
217 ms |
6648 KB |
Output is correct |
10 |
Correct |
219 ms |
6776 KB |
Output is correct |
11 |
Correct |
219 ms |
6524 KB |
Output is correct |
12 |
Correct |
225 ms |
7100 KB |
Output is correct |
13 |
Correct |
214 ms |
6776 KB |
Output is correct |
14 |
Correct |
220 ms |
6264 KB |
Output is correct |
15 |
Correct |
221 ms |
6776 KB |
Output is correct |
16 |
Correct |
22 ms |
4096 KB |
Output is correct |
17 |
Correct |
23 ms |
4096 KB |
Output is correct |
18 |
Correct |
20 ms |
4096 KB |
Output is correct |
19 |
Correct |
22 ms |
4096 KB |
Output is correct |
20 |
Correct |
22 ms |
4096 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
179 ms |
7416 KB |
Output is correct |
2 |
Correct |
178 ms |
7416 KB |
Output is correct |
3 |
Correct |
186 ms |
7416 KB |
Output is correct |
4 |
Correct |
178 ms |
7416 KB |
Output is correct |
5 |
Correct |
178 ms |
7416 KB |
Output is correct |
6 |
Correct |
221 ms |
6392 KB |
Output is correct |
7 |
Correct |
222 ms |
6136 KB |
Output is correct |
8 |
Correct |
221 ms |
6776 KB |
Output is correct |
9 |
Correct |
217 ms |
6648 KB |
Output is correct |
10 |
Correct |
219 ms |
6776 KB |
Output is correct |
11 |
Correct |
219 ms |
6524 KB |
Output is correct |
12 |
Correct |
225 ms |
7100 KB |
Output is correct |
13 |
Correct |
214 ms |
6776 KB |
Output is correct |
14 |
Correct |
220 ms |
6264 KB |
Output is correct |
15 |
Correct |
221 ms |
6776 KB |
Output is correct |
16 |
Correct |
22 ms |
4096 KB |
Output is correct |
17 |
Correct |
23 ms |
4096 KB |
Output is correct |
18 |
Correct |
20 ms |
4096 KB |
Output is correct |
19 |
Correct |
22 ms |
4096 KB |
Output is correct |
20 |
Correct |
22 ms |
4096 KB |
Output is correct |
21 |
Execution timed out |
2083 ms |
1900 KB |
Time limit exceeded |
22 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1745 ms |
1736 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
179 ms |
7416 KB |
Output is correct |
2 |
Correct |
178 ms |
7416 KB |
Output is correct |
3 |
Correct |
186 ms |
7416 KB |
Output is correct |
4 |
Correct |
178 ms |
7416 KB |
Output is correct |
5 |
Correct |
178 ms |
7416 KB |
Output is correct |
6 |
Correct |
221 ms |
6392 KB |
Output is correct |
7 |
Correct |
222 ms |
6136 KB |
Output is correct |
8 |
Correct |
221 ms |
6776 KB |
Output is correct |
9 |
Correct |
217 ms |
6648 KB |
Output is correct |
10 |
Correct |
219 ms |
6776 KB |
Output is correct |
11 |
Correct |
219 ms |
6524 KB |
Output is correct |
12 |
Correct |
225 ms |
7100 KB |
Output is correct |
13 |
Correct |
214 ms |
6776 KB |
Output is correct |
14 |
Correct |
220 ms |
6264 KB |
Output is correct |
15 |
Correct |
221 ms |
6776 KB |
Output is correct |
16 |
Correct |
22 ms |
4096 KB |
Output is correct |
17 |
Correct |
23 ms |
4096 KB |
Output is correct |
18 |
Correct |
20 ms |
4096 KB |
Output is correct |
19 |
Correct |
22 ms |
4096 KB |
Output is correct |
20 |
Correct |
22 ms |
4096 KB |
Output is correct |
21 |
Execution timed out |
2083 ms |
1900 KB |
Time limit exceeded |
22 |
Halted |
0 ms |
0 KB |
- |