//Pantyhose(black) + glasses = infinity
#include <bits/stdc++.h>
using namespace std;
#define debug(x) cerr << #x << " = " << x << '\n';
#define BP() cerr << "OK!\n";
#define PR(A, n) {cerr << #A << " = "; for (int _=1; _<=n; ++_) cerr << A[_] << ' '; cerr << '\n';}
#define PR0(A, n) {cerr << #A << " = "; for (int _=0; _<n; ++_) cerr << A[_] << ' '; cerr << '\n';}
#define FILE_NAME "boat"
const int MAX_N = 502;
const int MOD = 1000000007;
const int64_t INF = 1e18;
const int64_t INF2 = 1e16;
int n, l[MAX_N], r[MAX_N];
vector<pair<int, int> > seg;
int64_t C1[MAX_N][MAX_N], C2[2*MAX_N][MAX_N];
int64_t inv[MAX_N], inv_fact[MAX_N], f[MAX_N][2*MAX_N], P[2*MAX_N][MAX_N];
void read_input() {
cin >> n;
for (int i=1; i<=n; ++i)
cin >> l[i] >> r[i];
}
void init() {
vector<int> x;
for (int i=1; i<=n; ++i) {
x.push_back(l[i]);
x.push_back(r[i]+1);
}
sort(x.begin(), x.end());
x.resize(unique(x.begin(), x.end()) - x.begin());
seg.push_back({0, 0});
for (int i=0; i+1<x.size(); ++i) {
seg.push_back({x[i], x[i+1]-1});
// cerr << seg.back().first << ' ' << seg.back().second << '\n';
}
inv[1] = 1;
inv_fact[0] = inv_fact[1] = 1;
for (int i=2; i<=n; ++i) {
inv[i] = MOD - MOD/i*inv[MOD%i]%MOD;
inv_fact[i] = inv_fact[i-1] * inv[i] % MOD;
}
// debug(inv[2]*2%MOD);
}
int64_t comb(int n, int k) {
if (n<0 || n<k)
return 0;
int64_t res = 1;
for (int i=n-k+1; i<=n; ++i) {
res = res * i;
if (res>INF2)
res %= MOD;
}
return res % MOD * inv_fact[k] % MOD;
}
void dp() {
for (int i=1; i<seg.size(); ++i) {
for (int j=1; j<=n; ++j)
C2[i][j] = comb(seg[i].second - seg[i].first + 1, j);
}
for (int i=0; i<=n; ++i)
C1[i][i] = C1[i][0] = 1;
for (int i=1; i<=n; ++i) {
for (int j=1; j<i; ++j)
C1[i][j] = (C1[i-1][j] + C1[i-1][j-1]) % MOD;
}
for (int i=1; i<seg.size(); ++i) {
for (int k=1; k<=n; ++k) {
for (int j=1; j<=k; ++j) {
P[i][k] = P[i][k] + C2[i][j] * C1[k-1][j-1];
if (P[i][k]>INF)
P[i][k] %= MOD;
}
P[i][k] %= MOD;
}
}
// debug(P[1][1]);
for (int i=0; i<seg.size(); ++i)
f[0][i] = 1;
for (int i=0; i<=n; ++i)
f[i][0] = 1;
int64_t res = 0;
for (int i=1; i<=n; ++i) {
for (int j=1; j<seg.size(); ++j) {
f[i][j] = f[i][j-1];
int cnt = 0;
for (int k=i; k>=1; --k) {
if (l[k]<=seg[j].first && seg[j].second<=r[k]) {
++cnt;
// if (i==3 && j==1 && k==1)
// debug(tmp);
f[i][j] = (f[i][j] + f[k-1][j-1] * P[j][cnt]);
if (f[i][j]>INF)
f[i][j] %= MOD;
}
}
f[i][j] %= MOD;
}
}
// debug(f[3][0]);
cout << (f[n][seg.size()-1] - 1 + MOD) % MOD;
}
int main() {
#ifdef GLASSES_GIRL
freopen(FILE_NAME".in", "r", stdin);
freopen(FILE_NAME".out", "w", stdout);
#endif
ios::sync_with_stdio(0); cin.tie(0);
read_input();
init();
dp();
}
Compilation message
boat.cpp: In function 'void init()':
boat.cpp:41:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i=0; i+1<x.size(); ++i) {
~~~^~~~~~~~~
boat.cpp: In function 'void dp()':
boat.cpp:71:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i=1; i<seg.size(); ++i) {
~^~~~~~~~~~~
boat.cpp:83:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i=1; i<seg.size(); ++i) {
~^~~~~~~~~~~
boat.cpp:95:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i=0; i<seg.size(); ++i)
~^~~~~~~~~~~
boat.cpp:103:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int j=1; j<seg.size(); ++j) {
~^~~~~~~~~~~
boat.cpp:100:10: warning: unused variable 'res' [-Wunused-variable]
int64_t res = 0;
^~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
859 ms |
14312 KB |
Output is correct |
2 |
Correct |
848 ms |
14200 KB |
Output is correct |
3 |
Correct |
839 ms |
14456 KB |
Output is correct |
4 |
Correct |
856 ms |
14252 KB |
Output is correct |
5 |
Correct |
838 ms |
14332 KB |
Output is correct |
6 |
Correct |
626 ms |
14196 KB |
Output is correct |
7 |
Correct |
628 ms |
14196 KB |
Output is correct |
8 |
Correct |
666 ms |
14328 KB |
Output is correct |
9 |
Correct |
609 ms |
14368 KB |
Output is correct |
10 |
Correct |
659 ms |
14164 KB |
Output is correct |
11 |
Correct |
678 ms |
14368 KB |
Output is correct |
12 |
Correct |
649 ms |
14328 KB |
Output is correct |
13 |
Correct |
692 ms |
14300 KB |
Output is correct |
14 |
Correct |
661 ms |
14328 KB |
Output is correct |
15 |
Correct |
720 ms |
14308 KB |
Output is correct |
16 |
Correct |
164 ms |
6476 KB |
Output is correct |
17 |
Correct |
169 ms |
6648 KB |
Output is correct |
18 |
Correct |
155 ms |
6520 KB |
Output is correct |
19 |
Correct |
168 ms |
6748 KB |
Output is correct |
20 |
Correct |
160 ms |
6492 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
859 ms |
14312 KB |
Output is correct |
2 |
Correct |
848 ms |
14200 KB |
Output is correct |
3 |
Correct |
839 ms |
14456 KB |
Output is correct |
4 |
Correct |
856 ms |
14252 KB |
Output is correct |
5 |
Correct |
838 ms |
14332 KB |
Output is correct |
6 |
Correct |
626 ms |
14196 KB |
Output is correct |
7 |
Correct |
628 ms |
14196 KB |
Output is correct |
8 |
Correct |
666 ms |
14328 KB |
Output is correct |
9 |
Correct |
609 ms |
14368 KB |
Output is correct |
10 |
Correct |
659 ms |
14164 KB |
Output is correct |
11 |
Correct |
678 ms |
14368 KB |
Output is correct |
12 |
Correct |
649 ms |
14328 KB |
Output is correct |
13 |
Correct |
692 ms |
14300 KB |
Output is correct |
14 |
Correct |
661 ms |
14328 KB |
Output is correct |
15 |
Correct |
720 ms |
14308 KB |
Output is correct |
16 |
Correct |
164 ms |
6476 KB |
Output is correct |
17 |
Correct |
169 ms |
6648 KB |
Output is correct |
18 |
Correct |
155 ms |
6520 KB |
Output is correct |
19 |
Correct |
168 ms |
6748 KB |
Output is correct |
20 |
Correct |
160 ms |
6492 KB |
Output is correct |
21 |
Correct |
743 ms |
13496 KB |
Output is correct |
22 |
Correct |
690 ms |
13604 KB |
Output is correct |
23 |
Correct |
688 ms |
13432 KB |
Output is correct |
24 |
Correct |
678 ms |
13532 KB |
Output is correct |
25 |
Correct |
729 ms |
13496 KB |
Output is correct |
26 |
Correct |
388 ms |
13304 KB |
Output is correct |
27 |
Correct |
446 ms |
13396 KB |
Output is correct |
28 |
Correct |
373 ms |
13152 KB |
Output is correct |
29 |
Correct |
372 ms |
13288 KB |
Output is correct |
30 |
Correct |
567 ms |
14184 KB |
Output is correct |
31 |
Correct |
536 ms |
14200 KB |
Output is correct |
32 |
Correct |
578 ms |
14140 KB |
Output is correct |
33 |
Correct |
551 ms |
14328 KB |
Output is correct |
34 |
Correct |
539 ms |
14244 KB |
Output is correct |
35 |
Correct |
843 ms |
14404 KB |
Output is correct |
36 |
Correct |
784 ms |
14188 KB |
Output is correct |
37 |
Correct |
835 ms |
14276 KB |
Output is correct |
38 |
Correct |
878 ms |
14224 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
19 ms |
2944 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
859 ms |
14312 KB |
Output is correct |
2 |
Correct |
848 ms |
14200 KB |
Output is correct |
3 |
Correct |
839 ms |
14456 KB |
Output is correct |
4 |
Correct |
856 ms |
14252 KB |
Output is correct |
5 |
Correct |
838 ms |
14332 KB |
Output is correct |
6 |
Correct |
626 ms |
14196 KB |
Output is correct |
7 |
Correct |
628 ms |
14196 KB |
Output is correct |
8 |
Correct |
666 ms |
14328 KB |
Output is correct |
9 |
Correct |
609 ms |
14368 KB |
Output is correct |
10 |
Correct |
659 ms |
14164 KB |
Output is correct |
11 |
Correct |
678 ms |
14368 KB |
Output is correct |
12 |
Correct |
649 ms |
14328 KB |
Output is correct |
13 |
Correct |
692 ms |
14300 KB |
Output is correct |
14 |
Correct |
661 ms |
14328 KB |
Output is correct |
15 |
Correct |
720 ms |
14308 KB |
Output is correct |
16 |
Correct |
164 ms |
6476 KB |
Output is correct |
17 |
Correct |
169 ms |
6648 KB |
Output is correct |
18 |
Correct |
155 ms |
6520 KB |
Output is correct |
19 |
Correct |
168 ms |
6748 KB |
Output is correct |
20 |
Correct |
160 ms |
6492 KB |
Output is correct |
21 |
Correct |
743 ms |
13496 KB |
Output is correct |
22 |
Correct |
690 ms |
13604 KB |
Output is correct |
23 |
Correct |
688 ms |
13432 KB |
Output is correct |
24 |
Correct |
678 ms |
13532 KB |
Output is correct |
25 |
Correct |
729 ms |
13496 KB |
Output is correct |
26 |
Correct |
388 ms |
13304 KB |
Output is correct |
27 |
Correct |
446 ms |
13396 KB |
Output is correct |
28 |
Correct |
373 ms |
13152 KB |
Output is correct |
29 |
Correct |
372 ms |
13288 KB |
Output is correct |
30 |
Correct |
567 ms |
14184 KB |
Output is correct |
31 |
Correct |
536 ms |
14200 KB |
Output is correct |
32 |
Correct |
578 ms |
14140 KB |
Output is correct |
33 |
Correct |
551 ms |
14328 KB |
Output is correct |
34 |
Correct |
539 ms |
14244 KB |
Output is correct |
35 |
Correct |
843 ms |
14404 KB |
Output is correct |
36 |
Correct |
784 ms |
14188 KB |
Output is correct |
37 |
Correct |
835 ms |
14276 KB |
Output is correct |
38 |
Correct |
878 ms |
14224 KB |
Output is correct |
39 |
Incorrect |
19 ms |
2944 KB |
Output isn't correct |
40 |
Halted |
0 ms |
0 KB |
- |