#include <bits/stdc++.h>
#define int long long
using namespace std;
const int mod=1000000007;
int dp[2][1010][501],c[1001][501],n,a[501],b[501],l[1001],r[1001],id,f[501];
vector <pair <int, int>> v;
int pw(int a, int b){
if (!b)
return 1;
int t=pw(a,b>>1);
t=(t*t)%mod;
return (b&1?(t*a)%mod:t);
}
int32_t main(){
ios_base::sync_with_stdio(NULL);cin.tie(nullptr);
cin >> n;
f[0]=1;
for (int i=1;i<=n;i++){
cin >> a[i] >> b[i];
v.push_back({a[i],0});
v.push_back({b[i],1});
f[i]=f[i-1]*i%mod;
}
for (int i=1;i<=n;i++)
f[i]=pw(f[i],mod-2);
sort(v.begin(),v.end());
for (int i=0;i<v.size()-1;i++){
id++;
l[id]=v[i].first+v[i].second;
r[id]=v[i+1].first-1+v[i+1].second;
c[id][0]=1;
for (int j=1;j<=n;j++)
c[id][j]=c[id][j-1]*(r[id]-l[id]-j+2)%mod;
for (int j=2;j<=n;j++)
c[id][j]=c[id][j]*f[j]%mod;
}
for (int i=0;i<2;i++)
for (int k=0;k<=n;k++)
dp[i][id+1][k]=1;
for (int j=1;j<=id;j++)
for (int k=0;k<=n;k++)
dp[n&1^1][j][k]=(j>id?1:c[j][k]);
for (int i=n;i>=1;i--)
for (int j=id;j;j--)
for (int k=0;k<=n;k++){
if (k>r[j]-l[j]+1){
dp[i&1][j][k]=0;
continue;
}
dp[i&1][j][k]=dp[i&1^1][j][k]+(dp[i&1][j+1][0]-dp[i&1^1][j+1][0])*c[j][k]+(a[i]<=l[j]&&r[j]<=b[i])*dp[i&1^1][j][k+1];
dp[i&1][j][k]%=mod;
}
dp[1][1][0]=(dp[1][1][0]-1)%mod;
cout << (dp[1][1][0]+mod)%mod;
}
Compilation message
boat.cpp: In function 'int32_t main()':
boat.cpp:27:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
27 | for (int i=0;i<v.size()-1;i++){
| ~^~~~~~~~~~~
boat.cpp:42:17: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
42 | dp[n&1^1][j][k]=(j>id?1:c[j][k]);
| ~^~
boat.cpp:50:35: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
50 | dp[i&1][j][k]=dp[i&1^1][j][k]+(dp[i&1][j+1][0]-dp[i&1^1][j+1][0])*c[j][k]+(a[i]<=l[j]&&r[j]<=b[i])*dp[i&1^1][j][k+1];
| ~^~
boat.cpp:50:68: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
50 | dp[i&1][j][k]=dp[i&1^1][j][k]+(dp[i&1][j+1][0]-dp[i&1^1][j+1][0])*c[j][k]+(a[i]<=l[j]&&r[j]<=b[i])*dp[i&1^1][j][k+1];
| ~^~
boat.cpp:50:120: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
50 | dp[i&1][j][k]=dp[i&1^1][j][k]+(dp[i&1][j+1][0]-dp[i&1^1][j+1][0])*c[j][k]+(a[i]<=l[j]&&r[j]<=b[i])*dp[i&1^1][j][k+1];
| ~^~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
516 ms |
12064 KB |
Output is correct |
2 |
Correct |
570 ms |
12096 KB |
Output is correct |
3 |
Correct |
530 ms |
12148 KB |
Output is correct |
4 |
Correct |
531 ms |
12152 KB |
Output is correct |
5 |
Correct |
529 ms |
12260 KB |
Output is correct |
6 |
Correct |
523 ms |
12116 KB |
Output is correct |
7 |
Correct |
538 ms |
12132 KB |
Output is correct |
8 |
Correct |
623 ms |
12132 KB |
Output is correct |
9 |
Correct |
616 ms |
12132 KB |
Output is correct |
10 |
Correct |
619 ms |
12136 KB |
Output is correct |
11 |
Correct |
532 ms |
12268 KB |
Output is correct |
12 |
Correct |
556 ms |
12140 KB |
Output is correct |
13 |
Correct |
625 ms |
12136 KB |
Output is correct |
14 |
Correct |
584 ms |
12116 KB |
Output is correct |
15 |
Correct |
546 ms |
12116 KB |
Output is correct |
16 |
Correct |
290 ms |
12148 KB |
Output is correct |
17 |
Correct |
310 ms |
12136 KB |
Output is correct |
18 |
Correct |
282 ms |
12116 KB |
Output is correct |
19 |
Correct |
284 ms |
12116 KB |
Output is correct |
20 |
Correct |
288 ms |
12116 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
516 ms |
12064 KB |
Output is correct |
2 |
Correct |
570 ms |
12096 KB |
Output is correct |
3 |
Correct |
530 ms |
12148 KB |
Output is correct |
4 |
Correct |
531 ms |
12152 KB |
Output is correct |
5 |
Correct |
529 ms |
12260 KB |
Output is correct |
6 |
Correct |
523 ms |
12116 KB |
Output is correct |
7 |
Correct |
538 ms |
12132 KB |
Output is correct |
8 |
Correct |
623 ms |
12132 KB |
Output is correct |
9 |
Correct |
616 ms |
12132 KB |
Output is correct |
10 |
Correct |
619 ms |
12136 KB |
Output is correct |
11 |
Correct |
532 ms |
12268 KB |
Output is correct |
12 |
Correct |
556 ms |
12140 KB |
Output is correct |
13 |
Correct |
625 ms |
12136 KB |
Output is correct |
14 |
Correct |
584 ms |
12116 KB |
Output is correct |
15 |
Correct |
546 ms |
12116 KB |
Output is correct |
16 |
Correct |
290 ms |
12148 KB |
Output is correct |
17 |
Correct |
310 ms |
12136 KB |
Output is correct |
18 |
Correct |
282 ms |
12116 KB |
Output is correct |
19 |
Correct |
284 ms |
12116 KB |
Output is correct |
20 |
Correct |
288 ms |
12116 KB |
Output is correct |
21 |
Correct |
317 ms |
12136 KB |
Output is correct |
22 |
Correct |
284 ms |
12148 KB |
Output is correct |
23 |
Correct |
240 ms |
12116 KB |
Output is correct |
24 |
Correct |
272 ms |
12132 KB |
Output is correct |
25 |
Correct |
260 ms |
12236 KB |
Output is correct |
26 |
Correct |
243 ms |
12136 KB |
Output is correct |
27 |
Correct |
259 ms |
12116 KB |
Output is correct |
28 |
Correct |
243 ms |
12140 KB |
Output is correct |
29 |
Correct |
247 ms |
12132 KB |
Output is correct |
30 |
Correct |
526 ms |
12136 KB |
Output is correct |
31 |
Correct |
595 ms |
12132 KB |
Output is correct |
32 |
Correct |
563 ms |
12132 KB |
Output is correct |
33 |
Correct |
541 ms |
12136 KB |
Output is correct |
34 |
Correct |
510 ms |
12116 KB |
Output is correct |
35 |
Correct |
539 ms |
12148 KB |
Output is correct |
36 |
Correct |
543 ms |
12136 KB |
Output is correct |
37 |
Correct |
503 ms |
12116 KB |
Output is correct |
38 |
Correct |
506 ms |
12136 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
2644 KB |
Output is correct |
2 |
Correct |
7 ms |
2644 KB |
Output is correct |
3 |
Correct |
7 ms |
2644 KB |
Output is correct |
4 |
Correct |
8 ms |
2644 KB |
Output is correct |
5 |
Correct |
8 ms |
2720 KB |
Output is correct |
6 |
Correct |
10 ms |
2644 KB |
Output is correct |
7 |
Correct |
7 ms |
2644 KB |
Output is correct |
8 |
Correct |
11 ms |
2712 KB |
Output is correct |
9 |
Correct |
8 ms |
2644 KB |
Output is correct |
10 |
Correct |
7 ms |
2644 KB |
Output is correct |
11 |
Correct |
8 ms |
2644 KB |
Output is correct |
12 |
Correct |
7 ms |
2644 KB |
Output is correct |
13 |
Correct |
7 ms |
2644 KB |
Output is correct |
14 |
Correct |
8 ms |
2720 KB |
Output is correct |
15 |
Correct |
7 ms |
2716 KB |
Output is correct |
16 |
Correct |
5 ms |
2716 KB |
Output is correct |
17 |
Correct |
5 ms |
2644 KB |
Output is correct |
18 |
Correct |
5 ms |
2644 KB |
Output is correct |
19 |
Correct |
5 ms |
2644 KB |
Output is correct |
20 |
Correct |
6 ms |
2644 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
516 ms |
12064 KB |
Output is correct |
2 |
Correct |
570 ms |
12096 KB |
Output is correct |
3 |
Correct |
530 ms |
12148 KB |
Output is correct |
4 |
Correct |
531 ms |
12152 KB |
Output is correct |
5 |
Correct |
529 ms |
12260 KB |
Output is correct |
6 |
Correct |
523 ms |
12116 KB |
Output is correct |
7 |
Correct |
538 ms |
12132 KB |
Output is correct |
8 |
Correct |
623 ms |
12132 KB |
Output is correct |
9 |
Correct |
616 ms |
12132 KB |
Output is correct |
10 |
Correct |
619 ms |
12136 KB |
Output is correct |
11 |
Correct |
532 ms |
12268 KB |
Output is correct |
12 |
Correct |
556 ms |
12140 KB |
Output is correct |
13 |
Correct |
625 ms |
12136 KB |
Output is correct |
14 |
Correct |
584 ms |
12116 KB |
Output is correct |
15 |
Correct |
546 ms |
12116 KB |
Output is correct |
16 |
Correct |
290 ms |
12148 KB |
Output is correct |
17 |
Correct |
310 ms |
12136 KB |
Output is correct |
18 |
Correct |
282 ms |
12116 KB |
Output is correct |
19 |
Correct |
284 ms |
12116 KB |
Output is correct |
20 |
Correct |
288 ms |
12116 KB |
Output is correct |
21 |
Correct |
317 ms |
12136 KB |
Output is correct |
22 |
Correct |
284 ms |
12148 KB |
Output is correct |
23 |
Correct |
240 ms |
12116 KB |
Output is correct |
24 |
Correct |
272 ms |
12132 KB |
Output is correct |
25 |
Correct |
260 ms |
12236 KB |
Output is correct |
26 |
Correct |
243 ms |
12136 KB |
Output is correct |
27 |
Correct |
259 ms |
12116 KB |
Output is correct |
28 |
Correct |
243 ms |
12140 KB |
Output is correct |
29 |
Correct |
247 ms |
12132 KB |
Output is correct |
30 |
Correct |
526 ms |
12136 KB |
Output is correct |
31 |
Correct |
595 ms |
12132 KB |
Output is correct |
32 |
Correct |
563 ms |
12132 KB |
Output is correct |
33 |
Correct |
541 ms |
12136 KB |
Output is correct |
34 |
Correct |
510 ms |
12116 KB |
Output is correct |
35 |
Correct |
539 ms |
12148 KB |
Output is correct |
36 |
Correct |
543 ms |
12136 KB |
Output is correct |
37 |
Correct |
503 ms |
12116 KB |
Output is correct |
38 |
Correct |
506 ms |
12136 KB |
Output is correct |
39 |
Correct |
7 ms |
2644 KB |
Output is correct |
40 |
Correct |
7 ms |
2644 KB |
Output is correct |
41 |
Correct |
7 ms |
2644 KB |
Output is correct |
42 |
Correct |
8 ms |
2644 KB |
Output is correct |
43 |
Correct |
8 ms |
2720 KB |
Output is correct |
44 |
Correct |
10 ms |
2644 KB |
Output is correct |
45 |
Correct |
7 ms |
2644 KB |
Output is correct |
46 |
Correct |
11 ms |
2712 KB |
Output is correct |
47 |
Correct |
8 ms |
2644 KB |
Output is correct |
48 |
Correct |
7 ms |
2644 KB |
Output is correct |
49 |
Correct |
8 ms |
2644 KB |
Output is correct |
50 |
Correct |
7 ms |
2644 KB |
Output is correct |
51 |
Correct |
7 ms |
2644 KB |
Output is correct |
52 |
Correct |
8 ms |
2720 KB |
Output is correct |
53 |
Correct |
7 ms |
2716 KB |
Output is correct |
54 |
Correct |
5 ms |
2716 KB |
Output is correct |
55 |
Correct |
5 ms |
2644 KB |
Output is correct |
56 |
Correct |
5 ms |
2644 KB |
Output is correct |
57 |
Correct |
5 ms |
2644 KB |
Output is correct |
58 |
Correct |
6 ms |
2644 KB |
Output is correct |
59 |
Correct |
857 ms |
12144 KB |
Output is correct |
60 |
Correct |
821 ms |
12116 KB |
Output is correct |
61 |
Correct |
867 ms |
12136 KB |
Output is correct |
62 |
Correct |
886 ms |
12132 KB |
Output is correct |
63 |
Correct |
876 ms |
12236 KB |
Output is correct |
64 |
Correct |
920 ms |
12132 KB |
Output is correct |
65 |
Correct |
875 ms |
12136 KB |
Output is correct |
66 |
Correct |
868 ms |
12116 KB |
Output is correct |
67 |
Correct |
875 ms |
12136 KB |
Output is correct |
68 |
Correct |
888 ms |
12148 KB |
Output is correct |
69 |
Correct |
839 ms |
12116 KB |
Output is correct |
70 |
Correct |
842 ms |
12136 KB |
Output is correct |
71 |
Correct |
892 ms |
12140 KB |
Output is correct |
72 |
Correct |
857 ms |
12116 KB |
Output is correct |
73 |
Correct |
868 ms |
12144 KB |
Output is correct |
74 |
Correct |
330 ms |
12104 KB |
Output is correct |
75 |
Correct |
304 ms |
12136 KB |
Output is correct |
76 |
Correct |
340 ms |
12136 KB |
Output is correct |
77 |
Correct |
319 ms |
12236 KB |
Output is correct |
78 |
Correct |
307 ms |
12136 KB |
Output is correct |