#include <algorithm>
#include <cstring>
#include <cstdio>
using ll = long long;
constexpr int MOD = 1e9 + 7;
inline void Add(int &x, int y) { (x += y) >= MOD ? (x -= MOD) : 0; }
inline int quick_pow(int a, int n)
{
int res = 1;
while (n)
{
if (n & 1)
res = (ll)res * a % MOD;
a = (ll)a * a % MOD;
n >>= 1;
}
return res;
}
int lp[505], rp[505], app[1005], dp[1005][505], sum[1005][505], inv[505];
int main()
{
// freopen("uoj-204.in", "r", stdin);
int n, cnt = 0;
scanf("%d", &n);
for (int i = 0; i < n; i++)
{
scanf("%d%d", lp + i, rp + i);
app[cnt++] = lp[i];
app[cnt++] = ++rp[i];
}
std::sort(app, app + cnt);
cnt = std::unique(app, app + cnt) - app;
for (int i = 0; i < n; i++)
{
lp[i] = std::lower_bound(app, app + cnt, lp[i]) - app;
rp[i] = std::lower_bound(app, app + cnt, rp[i]) - app;
}
inv[0] = inv[1] = 1;
for (int i = 2; i <= n; i++)
inv[i] = (ll)(MOD - MOD / i) * inv[MOD % i] % MOD;
dp[0][0] = 1;
for (int i = 0; i < n; i++)
{
for (int j = 0; j < cnt; j++)
{
for (int k = 0; k <= i; k++)
{
sum[j + 1][k] = sum[j][k];
Add(sum[j + 1][k], dp[j][k]);
}
}
for (int j = lp[i]; j < rp[i]; j++)
{
int len = app[j + 1] - app[j], one = 0;
for (int k = i; k >= 0; k--)
{
dp[j][k + 1] = (dp[j][k + 1] + (ll)dp[j][k] * (len - k) % MOD * inv[k + 1]) % MOD;
Add(one, sum[j][k]);
}
dp[j][1] = (dp[j][1] + (ll)one * len) % MOD;
}
}
int ans = MOD - 1;
for (int i = 0; i < cnt; i++)
{
for (int j = 0; j <= n; j++)
Add(ans, dp[i][j]);
}
printf("%d\n", ans);
return 0;
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:24:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &n);
~~~~~^~~~~~~~~~
boat.cpp:27:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", lp + i, rp + i);
~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
116 ms |
4332 KB |
Output is correct |
2 |
Correct |
123 ms |
4388 KB |
Output is correct |
3 |
Correct |
140 ms |
4344 KB |
Output is correct |
4 |
Correct |
130 ms |
4232 KB |
Output is correct |
5 |
Correct |
125 ms |
4216 KB |
Output is correct |
6 |
Correct |
138 ms |
4208 KB |
Output is correct |
7 |
Correct |
134 ms |
4220 KB |
Output is correct |
8 |
Correct |
131 ms |
4208 KB |
Output is correct |
9 |
Correct |
140 ms |
4236 KB |
Output is correct |
10 |
Correct |
106 ms |
4316 KB |
Output is correct |
11 |
Correct |
112 ms |
4216 KB |
Output is correct |
12 |
Correct |
109 ms |
4216 KB |
Output is correct |
13 |
Correct |
109 ms |
4344 KB |
Output is correct |
14 |
Correct |
115 ms |
4344 KB |
Output is correct |
15 |
Correct |
108 ms |
4316 KB |
Output is correct |
16 |
Correct |
21 ms |
1024 KB |
Output is correct |
17 |
Correct |
24 ms |
1144 KB |
Output is correct |
18 |
Correct |
26 ms |
1024 KB |
Output is correct |
19 |
Correct |
25 ms |
1152 KB |
Output is correct |
20 |
Correct |
25 ms |
1144 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
116 ms |
4332 KB |
Output is correct |
2 |
Correct |
123 ms |
4388 KB |
Output is correct |
3 |
Correct |
140 ms |
4344 KB |
Output is correct |
4 |
Correct |
130 ms |
4232 KB |
Output is correct |
5 |
Correct |
125 ms |
4216 KB |
Output is correct |
6 |
Correct |
138 ms |
4208 KB |
Output is correct |
7 |
Correct |
134 ms |
4220 KB |
Output is correct |
8 |
Correct |
131 ms |
4208 KB |
Output is correct |
9 |
Correct |
140 ms |
4236 KB |
Output is correct |
10 |
Correct |
106 ms |
4316 KB |
Output is correct |
11 |
Correct |
112 ms |
4216 KB |
Output is correct |
12 |
Correct |
109 ms |
4216 KB |
Output is correct |
13 |
Correct |
109 ms |
4344 KB |
Output is correct |
14 |
Correct |
115 ms |
4344 KB |
Output is correct |
15 |
Correct |
108 ms |
4316 KB |
Output is correct |
16 |
Correct |
21 ms |
1024 KB |
Output is correct |
17 |
Correct |
24 ms |
1144 KB |
Output is correct |
18 |
Correct |
26 ms |
1024 KB |
Output is correct |
19 |
Correct |
25 ms |
1152 KB |
Output is correct |
20 |
Correct |
25 ms |
1144 KB |
Output is correct |
21 |
Correct |
349 ms |
3968 KB |
Output is correct |
22 |
Correct |
274 ms |
3968 KB |
Output is correct |
23 |
Correct |
286 ms |
3960 KB |
Output is correct |
24 |
Correct |
320 ms |
3840 KB |
Output is correct |
25 |
Correct |
342 ms |
3960 KB |
Output is correct |
26 |
Correct |
331 ms |
3732 KB |
Output is correct |
27 |
Correct |
347 ms |
3832 KB |
Output is correct |
28 |
Correct |
399 ms |
3832 KB |
Output is correct |
29 |
Correct |
459 ms |
3804 KB |
Output is correct |
30 |
Correct |
135 ms |
4416 KB |
Output is correct |
31 |
Correct |
125 ms |
4324 KB |
Output is correct |
32 |
Correct |
126 ms |
4216 KB |
Output is correct |
33 |
Correct |
143 ms |
4352 KB |
Output is correct |
34 |
Correct |
128 ms |
4252 KB |
Output is correct |
35 |
Correct |
138 ms |
4216 KB |
Output is correct |
36 |
Correct |
128 ms |
4240 KB |
Output is correct |
37 |
Correct |
145 ms |
4252 KB |
Output is correct |
38 |
Correct |
110 ms |
4216 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
1152 KB |
Output is correct |
2 |
Correct |
7 ms |
1152 KB |
Output is correct |
3 |
Correct |
7 ms |
1280 KB |
Output is correct |
4 |
Correct |
8 ms |
1152 KB |
Output is correct |
5 |
Correct |
11 ms |
1152 KB |
Output is correct |
6 |
Correct |
9 ms |
1152 KB |
Output is correct |
7 |
Correct |
9 ms |
1152 KB |
Output is correct |
8 |
Correct |
11 ms |
1152 KB |
Output is correct |
9 |
Correct |
11 ms |
1152 KB |
Output is correct |
10 |
Correct |
8 ms |
1152 KB |
Output is correct |
11 |
Correct |
6 ms |
1152 KB |
Output is correct |
12 |
Correct |
6 ms |
1152 KB |
Output is correct |
13 |
Correct |
7 ms |
1152 KB |
Output is correct |
14 |
Correct |
8 ms |
1152 KB |
Output is correct |
15 |
Correct |
9 ms |
1152 KB |
Output is correct |
16 |
Correct |
6 ms |
896 KB |
Output is correct |
17 |
Correct |
5 ms |
768 KB |
Output is correct |
18 |
Correct |
5 ms |
768 KB |
Output is correct |
19 |
Correct |
5 ms |
768 KB |
Output is correct |
20 |
Correct |
6 ms |
768 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
116 ms |
4332 KB |
Output is correct |
2 |
Correct |
123 ms |
4388 KB |
Output is correct |
3 |
Correct |
140 ms |
4344 KB |
Output is correct |
4 |
Correct |
130 ms |
4232 KB |
Output is correct |
5 |
Correct |
125 ms |
4216 KB |
Output is correct |
6 |
Correct |
138 ms |
4208 KB |
Output is correct |
7 |
Correct |
134 ms |
4220 KB |
Output is correct |
8 |
Correct |
131 ms |
4208 KB |
Output is correct |
9 |
Correct |
140 ms |
4236 KB |
Output is correct |
10 |
Correct |
106 ms |
4316 KB |
Output is correct |
11 |
Correct |
112 ms |
4216 KB |
Output is correct |
12 |
Correct |
109 ms |
4216 KB |
Output is correct |
13 |
Correct |
109 ms |
4344 KB |
Output is correct |
14 |
Correct |
115 ms |
4344 KB |
Output is correct |
15 |
Correct |
108 ms |
4316 KB |
Output is correct |
16 |
Correct |
21 ms |
1024 KB |
Output is correct |
17 |
Correct |
24 ms |
1144 KB |
Output is correct |
18 |
Correct |
26 ms |
1024 KB |
Output is correct |
19 |
Correct |
25 ms |
1152 KB |
Output is correct |
20 |
Correct |
25 ms |
1144 KB |
Output is correct |
21 |
Correct |
349 ms |
3968 KB |
Output is correct |
22 |
Correct |
274 ms |
3968 KB |
Output is correct |
23 |
Correct |
286 ms |
3960 KB |
Output is correct |
24 |
Correct |
320 ms |
3840 KB |
Output is correct |
25 |
Correct |
342 ms |
3960 KB |
Output is correct |
26 |
Correct |
331 ms |
3732 KB |
Output is correct |
27 |
Correct |
347 ms |
3832 KB |
Output is correct |
28 |
Correct |
399 ms |
3832 KB |
Output is correct |
29 |
Correct |
459 ms |
3804 KB |
Output is correct |
30 |
Correct |
135 ms |
4416 KB |
Output is correct |
31 |
Correct |
125 ms |
4324 KB |
Output is correct |
32 |
Correct |
126 ms |
4216 KB |
Output is correct |
33 |
Correct |
143 ms |
4352 KB |
Output is correct |
34 |
Correct |
128 ms |
4252 KB |
Output is correct |
35 |
Correct |
138 ms |
4216 KB |
Output is correct |
36 |
Correct |
128 ms |
4240 KB |
Output is correct |
37 |
Correct |
145 ms |
4252 KB |
Output is correct |
38 |
Correct |
110 ms |
4216 KB |
Output is correct |
39 |
Correct |
6 ms |
1152 KB |
Output is correct |
40 |
Correct |
7 ms |
1152 KB |
Output is correct |
41 |
Correct |
7 ms |
1280 KB |
Output is correct |
42 |
Correct |
8 ms |
1152 KB |
Output is correct |
43 |
Correct |
11 ms |
1152 KB |
Output is correct |
44 |
Correct |
9 ms |
1152 KB |
Output is correct |
45 |
Correct |
9 ms |
1152 KB |
Output is correct |
46 |
Correct |
11 ms |
1152 KB |
Output is correct |
47 |
Correct |
11 ms |
1152 KB |
Output is correct |
48 |
Correct |
8 ms |
1152 KB |
Output is correct |
49 |
Correct |
6 ms |
1152 KB |
Output is correct |
50 |
Correct |
6 ms |
1152 KB |
Output is correct |
51 |
Correct |
7 ms |
1152 KB |
Output is correct |
52 |
Correct |
8 ms |
1152 KB |
Output is correct |
53 |
Correct |
9 ms |
1152 KB |
Output is correct |
54 |
Correct |
6 ms |
896 KB |
Output is correct |
55 |
Correct |
5 ms |
768 KB |
Output is correct |
56 |
Correct |
5 ms |
768 KB |
Output is correct |
57 |
Correct |
5 ms |
768 KB |
Output is correct |
58 |
Correct |
6 ms |
768 KB |
Output is correct |
59 |
Correct |
546 ms |
4348 KB |
Output is correct |
60 |
Correct |
490 ms |
4344 KB |
Output is correct |
61 |
Correct |
453 ms |
4376 KB |
Output is correct |
62 |
Correct |
598 ms |
4444 KB |
Output is correct |
63 |
Correct |
566 ms |
4224 KB |
Output is correct |
64 |
Correct |
722 ms |
4276 KB |
Output is correct |
65 |
Correct |
721 ms |
4316 KB |
Output is correct |
66 |
Correct |
650 ms |
4428 KB |
Output is correct |
67 |
Correct |
724 ms |
4572 KB |
Output is correct |
68 |
Correct |
752 ms |
4444 KB |
Output is correct |
69 |
Correct |
504 ms |
4344 KB |
Output is correct |
70 |
Correct |
561 ms |
4344 KB |
Output is correct |
71 |
Correct |
474 ms |
4344 KB |
Output is correct |
72 |
Correct |
513 ms |
4344 KB |
Output is correct |
73 |
Correct |
550 ms |
4436 KB |
Output is correct |
74 |
Correct |
77 ms |
1024 KB |
Output is correct |
75 |
Correct |
72 ms |
1024 KB |
Output is correct |
76 |
Correct |
73 ms |
1024 KB |
Output is correct |
77 |
Correct |
74 ms |
1024 KB |
Output is correct |
78 |
Correct |
77 ms |
1144 KB |
Output is correct |