#include<bits/stdc++.h>
#define fi first
#define se second
#define all(x) (x).begin() , (x).end()
#define rall(x) (x).rbegin() , (x).rend()
#define mkp make_pair
#define pb push_back
#define len(x) (int)(x).size()
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
//#define int long long
const int MOD = (int)1e9 + 7, N = 502;
int pw(int a , int b){
if(b == 0)return 1;
int ans = pw(a , b >> 1);
ans = (1ll * ans * ans) % MOD;
if(b & 1)
ans = (1ll * ans * a) % MOD;
return ans;
}
int f[4*N][N] , inv[N] , fact[N];
int C[N][N] , done[4*N][N] , cnt[4*N][N];
void mDD(ll &a){
if(a >= 1ll*MOD*MOD)
a-=1ll*MOD*MOD;
}
void md(int &a){
if(a >= MOD)a-=MOD;
}
void COMBA(vector<pii>&lines){
fact[0] = 1;
for(int i = 1 ; i < N; ++i)
fact[i] = (1ll * fact[i-1] * i) % MOD;
inv[N-1] = pw(fact[N-1], MOD-2);
for(int i = N-2;i>=0;--i)
inv[i] = (1ll * inv[i+1]*(i+1))%MOD;
for(int i = 0 ; i < N; ++i){
C[i][0] = 1;
for(int j = 1; j <= i ; ++j){
C[i][j] = C[i-1][j] + C[i-1][j-1];
md(C[i][j]);
}
}
/// fucking cnt[i][j]
for(int i = 1; i < len(lines); ++i){
for(int want = 0 ;want < N; ++want){
int len = lines[i].se - lines[i].fi + 1;
if(len < want)
done[i][want] = 0;
else{
ll answer = 1;
for(int j = len-want + 1; j<= len; ++j){
answer = (1ll * answer * j) % MOD;
}
answer = (1ll * answer * inv[want]) % MOD;
done[i][want] = answer;
}
}
}
for(int i = 0 ; i < len(lines); ++i){
for(int j = 1 ; j < N; ++j){
ll CNT = 0;
for(int k = 0 ; k < j; ++k){
CNT += (1ll * C[j-1][k] * done[i][j-k]);
mDD(CNT);
}
cnt[i][j] = CNT%MOD;
}
}
}
signed main(){
// ifstream cin("1_01.in");
ios_base::sync_with_stdio(0) , cin.tie(0) , cout.tie(0);
int n;cin >> n;
vector<pii>boats(n);
for(auto&i:boats)cin>>i.fi>>i.se;
/// lulz wtf is going on here
set < int > dots;
for(auto x : boats)
dots.insert(x.fi) , dots.insert(x.se);
vector<pii>lines;
lines.pb({0 , 0});
for(auto i : dots)
lines.pb(mkp(i , i));
auto it = dots.begin();
int prev = *it;
++it;
while(it != dots.end()){
if(prev + 1 <= *it-1)
lines.pb({prev + 1 , *it-1});
prev = *it;
++it;
}
sort(all(lines));
for(auto &i : boats){
int l = lower_bound(all(lines) , mkp(i.fi , -1))-lines.begin();
int r = lower_bound(all(lines) , mkp(i.se + 1 , -1))-lines.begin() - 1;
i = mkp(l , r);
}
COMBA(lines);
for(int i = 0 ; i < n; ++i)
f[0][i] = 1;
for(int i = 1; i < len(lines); ++i){
for(int j = 0; j < N; ++j)
f[i][j] = f[i-1][j];
/// what if we skip anybody
for(int j = 1; j <= n; ++j){
int cur = j;
int bad = 0;
ll DP=0;
for(int k = 1; k <= n , cur>0; ++k , --cur){
if(boats[cur-1].se < i || boats[cur-1].fi > i)
{bad++;continue;}
/// firstly update answer
DP += f[i-1][j-k]*1ll*cnt[i][k - bad];
mDD(DP);
}
f[i][j] += DP%MOD;
md(f[i][j]);
}
// cout << " I " << i << '\n';
// for(int j = 0 ; j <= n; ++j)
// cout << f[i][j] << ' ' ;
// cout << '\n';
}
cout << f[len(lines)-1][n];
return 0;
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:123:30: warning: left operand of comma operator has no effect [-Wunused-value]
for(int k = 1; k <= n , cur>0; ++k , --cur){
~~^~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
783 ms |
7416 KB |
Output is correct |
2 |
Correct |
783 ms |
7416 KB |
Output is correct |
3 |
Correct |
784 ms |
7544 KB |
Output is correct |
4 |
Correct |
791 ms |
7288 KB |
Output is correct |
5 |
Correct |
796 ms |
7340 KB |
Output is correct |
6 |
Correct |
688 ms |
7304 KB |
Output is correct |
7 |
Correct |
678 ms |
7288 KB |
Output is correct |
8 |
Correct |
686 ms |
7292 KB |
Output is correct |
9 |
Correct |
685 ms |
7416 KB |
Output is correct |
10 |
Correct |
720 ms |
7352 KB |
Output is correct |
11 |
Correct |
707 ms |
7288 KB |
Output is correct |
12 |
Correct |
679 ms |
7288 KB |
Output is correct |
13 |
Correct |
677 ms |
7440 KB |
Output is correct |
14 |
Correct |
676 ms |
7288 KB |
Output is correct |
15 |
Correct |
686 ms |
7416 KB |
Output is correct |
16 |
Correct |
138 ms |
2424 KB |
Output is correct |
17 |
Correct |
150 ms |
2552 KB |
Output is correct |
18 |
Correct |
142 ms |
2424 KB |
Output is correct |
19 |
Correct |
149 ms |
2552 KB |
Output is correct |
20 |
Correct |
146 ms |
2424 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
783 ms |
7416 KB |
Output is correct |
2 |
Correct |
783 ms |
7416 KB |
Output is correct |
3 |
Correct |
784 ms |
7544 KB |
Output is correct |
4 |
Correct |
791 ms |
7288 KB |
Output is correct |
5 |
Correct |
796 ms |
7340 KB |
Output is correct |
6 |
Correct |
688 ms |
7304 KB |
Output is correct |
7 |
Correct |
678 ms |
7288 KB |
Output is correct |
8 |
Correct |
686 ms |
7292 KB |
Output is correct |
9 |
Correct |
685 ms |
7416 KB |
Output is correct |
10 |
Correct |
720 ms |
7352 KB |
Output is correct |
11 |
Correct |
707 ms |
7288 KB |
Output is correct |
12 |
Correct |
679 ms |
7288 KB |
Output is correct |
13 |
Correct |
677 ms |
7440 KB |
Output is correct |
14 |
Correct |
676 ms |
7288 KB |
Output is correct |
15 |
Correct |
686 ms |
7416 KB |
Output is correct |
16 |
Correct |
138 ms |
2424 KB |
Output is correct |
17 |
Correct |
150 ms |
2552 KB |
Output is correct |
18 |
Correct |
142 ms |
2424 KB |
Output is correct |
19 |
Correct |
149 ms |
2552 KB |
Output is correct |
20 |
Correct |
146 ms |
2424 KB |
Output is correct |
21 |
Correct |
825 ms |
11244 KB |
Output is correct |
22 |
Correct |
821 ms |
11452 KB |
Output is correct |
23 |
Correct |
803 ms |
11256 KB |
Output is correct |
24 |
Correct |
820 ms |
11348 KB |
Output is correct |
25 |
Correct |
799 ms |
11256 KB |
Output is correct |
26 |
Correct |
730 ms |
10744 KB |
Output is correct |
27 |
Correct |
749 ms |
10872 KB |
Output is correct |
28 |
Correct |
750 ms |
10744 KB |
Output is correct |
29 |
Correct |
747 ms |
10872 KB |
Output is correct |
30 |
Correct |
996 ms |
12536 KB |
Output is correct |
31 |
Correct |
972 ms |
12336 KB |
Output is correct |
32 |
Correct |
1006 ms |
12416 KB |
Output is correct |
33 |
Correct |
975 ms |
12272 KB |
Output is correct |
34 |
Correct |
987 ms |
12540 KB |
Output is correct |
35 |
Correct |
747 ms |
7288 KB |
Output is correct |
36 |
Correct |
745 ms |
7424 KB |
Output is correct |
37 |
Correct |
764 ms |
7520 KB |
Output is correct |
38 |
Correct |
738 ms |
7344 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
213 ms |
3704 KB |
Output is correct |
2 |
Correct |
211 ms |
3832 KB |
Output is correct |
3 |
Correct |
214 ms |
3704 KB |
Output is correct |
4 |
Correct |
211 ms |
3708 KB |
Output is correct |
5 |
Correct |
213 ms |
3704 KB |
Output is correct |
6 |
Correct |
214 ms |
3708 KB |
Output is correct |
7 |
Correct |
211 ms |
3704 KB |
Output is correct |
8 |
Correct |
210 ms |
3832 KB |
Output is correct |
9 |
Correct |
213 ms |
3704 KB |
Output is correct |
10 |
Correct |
210 ms |
3792 KB |
Output is correct |
11 |
Correct |
213 ms |
3704 KB |
Output is correct |
12 |
Correct |
211 ms |
3704 KB |
Output is correct |
13 |
Correct |
211 ms |
3832 KB |
Output is correct |
14 |
Correct |
211 ms |
3704 KB |
Output is correct |
15 |
Correct |
211 ms |
3704 KB |
Output is correct |
16 |
Correct |
94 ms |
2424 KB |
Output is correct |
17 |
Correct |
95 ms |
2424 KB |
Output is correct |
18 |
Correct |
94 ms |
2424 KB |
Output is correct |
19 |
Correct |
94 ms |
2296 KB |
Output is correct |
20 |
Correct |
99 ms |
2432 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
783 ms |
7416 KB |
Output is correct |
2 |
Correct |
783 ms |
7416 KB |
Output is correct |
3 |
Correct |
784 ms |
7544 KB |
Output is correct |
4 |
Correct |
791 ms |
7288 KB |
Output is correct |
5 |
Correct |
796 ms |
7340 KB |
Output is correct |
6 |
Correct |
688 ms |
7304 KB |
Output is correct |
7 |
Correct |
678 ms |
7288 KB |
Output is correct |
8 |
Correct |
686 ms |
7292 KB |
Output is correct |
9 |
Correct |
685 ms |
7416 KB |
Output is correct |
10 |
Correct |
720 ms |
7352 KB |
Output is correct |
11 |
Correct |
707 ms |
7288 KB |
Output is correct |
12 |
Correct |
679 ms |
7288 KB |
Output is correct |
13 |
Correct |
677 ms |
7440 KB |
Output is correct |
14 |
Correct |
676 ms |
7288 KB |
Output is correct |
15 |
Correct |
686 ms |
7416 KB |
Output is correct |
16 |
Correct |
138 ms |
2424 KB |
Output is correct |
17 |
Correct |
150 ms |
2552 KB |
Output is correct |
18 |
Correct |
142 ms |
2424 KB |
Output is correct |
19 |
Correct |
149 ms |
2552 KB |
Output is correct |
20 |
Correct |
146 ms |
2424 KB |
Output is correct |
21 |
Correct |
825 ms |
11244 KB |
Output is correct |
22 |
Correct |
821 ms |
11452 KB |
Output is correct |
23 |
Correct |
803 ms |
11256 KB |
Output is correct |
24 |
Correct |
820 ms |
11348 KB |
Output is correct |
25 |
Correct |
799 ms |
11256 KB |
Output is correct |
26 |
Correct |
730 ms |
10744 KB |
Output is correct |
27 |
Correct |
749 ms |
10872 KB |
Output is correct |
28 |
Correct |
750 ms |
10744 KB |
Output is correct |
29 |
Correct |
747 ms |
10872 KB |
Output is correct |
30 |
Correct |
996 ms |
12536 KB |
Output is correct |
31 |
Correct |
972 ms |
12336 KB |
Output is correct |
32 |
Correct |
1006 ms |
12416 KB |
Output is correct |
33 |
Correct |
975 ms |
12272 KB |
Output is correct |
34 |
Correct |
987 ms |
12540 KB |
Output is correct |
35 |
Correct |
747 ms |
7288 KB |
Output is correct |
36 |
Correct |
745 ms |
7424 KB |
Output is correct |
37 |
Correct |
764 ms |
7520 KB |
Output is correct |
38 |
Correct |
738 ms |
7344 KB |
Output is correct |
39 |
Correct |
213 ms |
3704 KB |
Output is correct |
40 |
Correct |
211 ms |
3832 KB |
Output is correct |
41 |
Correct |
214 ms |
3704 KB |
Output is correct |
42 |
Correct |
211 ms |
3708 KB |
Output is correct |
43 |
Correct |
213 ms |
3704 KB |
Output is correct |
44 |
Correct |
214 ms |
3708 KB |
Output is correct |
45 |
Correct |
211 ms |
3704 KB |
Output is correct |
46 |
Correct |
210 ms |
3832 KB |
Output is correct |
47 |
Correct |
213 ms |
3704 KB |
Output is correct |
48 |
Correct |
210 ms |
3792 KB |
Output is correct |
49 |
Correct |
213 ms |
3704 KB |
Output is correct |
50 |
Correct |
211 ms |
3704 KB |
Output is correct |
51 |
Correct |
211 ms |
3832 KB |
Output is correct |
52 |
Correct |
211 ms |
3704 KB |
Output is correct |
53 |
Correct |
211 ms |
3704 KB |
Output is correct |
54 |
Correct |
94 ms |
2424 KB |
Output is correct |
55 |
Correct |
95 ms |
2424 KB |
Output is correct |
56 |
Correct |
94 ms |
2424 KB |
Output is correct |
57 |
Correct |
94 ms |
2296 KB |
Output is correct |
58 |
Correct |
99 ms |
2432 KB |
Output is correct |
59 |
Correct |
1538 ms |
13240 KB |
Output is correct |
60 |
Correct |
1539 ms |
13176 KB |
Output is correct |
61 |
Correct |
1528 ms |
13180 KB |
Output is correct |
62 |
Correct |
1546 ms |
13416 KB |
Output is correct |
63 |
Correct |
1530 ms |
13176 KB |
Output is correct |
64 |
Correct |
1522 ms |
13304 KB |
Output is correct |
65 |
Correct |
1502 ms |
13280 KB |
Output is correct |
66 |
Correct |
1491 ms |
13176 KB |
Output is correct |
67 |
Correct |
1507 ms |
13240 KB |
Output is correct |
68 |
Correct |
1511 ms |
13476 KB |
Output is correct |
69 |
Correct |
1468 ms |
13232 KB |
Output is correct |
70 |
Correct |
1468 ms |
13176 KB |
Output is correct |
71 |
Correct |
1463 ms |
13304 KB |
Output is correct |
72 |
Correct |
1453 ms |
13348 KB |
Output is correct |
73 |
Correct |
1459 ms |
13444 KB |
Output is correct |
74 |
Correct |
162 ms |
2556 KB |
Output is correct |
75 |
Correct |
160 ms |
2584 KB |
Output is correct |
76 |
Correct |
164 ms |
2552 KB |
Output is correct |
77 |
Correct |
158 ms |
2552 KB |
Output is correct |
78 |
Correct |
160 ms |
2552 KB |
Output is correct |