// Why am I so dumb? :c
// chrono::system_clock::now().time_since_epoch().count()
#include<bits/stdc++.h>
//#include<ext/pb_ds/assoc_container.hpp>
//#include<ext/pb_ds/tree_policy.hpp>
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second
using namespace std;
//using namespace __gnu_pbds;
typedef long long ll;
typedef pair<int, int> pii;
//template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int MAXN = (int)1e3 + 5;
const int MOD = (int)1e9 + 7;
int dp[2][MAXN][MAXN];
int mem[MAXN][MAXN];
vector<int> T;
pii arr[MAXN];
int n;
int addMod(int a, int b, int m = MOD) {
a += b;
if (m <= a) {
a -= m;
}
return a;
}
int mulMod(int a, int b, int m = MOD) {
return a * 1ll * b % m;
}
int binPow(int a, int b, int m = MOD) {
int ret = 1;
while (b > 0) {
if (b & 1) {
ret = mulMod(ret, a, m);
}
a = mulMod(a, a, m);
b >>= 1;
}
return ret;
}
void solve() {
scanf("%d", &n);
for (int i = 1; i <= n; ++i) {
scanf("%d %d", &arr[i].fi, &arr[i].se);
T.pb(arr[i].fi);
T.pb(arr[i].se + 1);
}
T.pb(0);
sort(all(T));
T.resize(unique(all(T)) - T.begin());
for (int i = 1; i <= n; ++i) {
arr[i].fi = lower_bound(all(T), arr[i].fi) - T.begin();
arr[i].se = lower_bound(all(T), arr[i].se + 1) - T.begin();
}
for (int i = 0; i + 1 < T.size(); ++i) {
int x = T[i + 1] - T[i];
mem[i][0] = 1;
for (int j = 1; j <= n; ++j) {
if (j > x) {
mem[i][j] = 0;
continue;
}
mem[i][j] = mulMod(mem[i][j - 1], mulMod(x - j + 1, binPow(j, MOD - 2)));
}
}
dp[0][0][0] = 1;
for (int i = 1; i <= n; ++i) {
for (int c = 0; c < T.size(); ++c) {
for (int cnt = 0; cnt <= n; ++cnt) {
dp[1][c][cnt] = dp[0][c][cnt];
}
}
int p = 0, w = 0;
for (int c = arr[i].fi; c < arr[i].se; ++c) {
for (int cnt = 1; cnt <= n; ++cnt) {
dp[1][c][cnt] = addMod(dp[1][c][cnt], dp[0][c][cnt - 1]);
}
while (p < c) {
for (int cnt = 0; cnt <= n; ++cnt) {
w = addMod(w, mulMod(dp[0][p][cnt], mem[p][cnt]));
}
++p;
}
dp[1][c][1] = addMod(dp[1][c][1], w);
}
for (int c = 0; c < T.size(); ++c) {
for (int cnt = 0; cnt <= n; ++cnt) {
dp[0][c][cnt] = dp[1][c][cnt];
}
}
}
int ans = 0;
for (int c = 0; c + 1 < T.size(); ++c) {
for (int cnt = 1; cnt <= n; ++cnt) {
ans = addMod(ans, mulMod(dp[0][c][cnt], mem[c][cnt]));
}
}
printf("%d\n", ans);
}
int main() {
int tt = 1;
while (tt--) {
solve();
}
return 0;
}
Compilation message
boat.cpp: In function 'void solve()':
boat.cpp:83:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int i = 0; i + 1 < T.size(); ++i) {
~~~~~~^~~~~~~~~~
boat.cpp:100:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int c = 0; c < T.size(); ++c) {
~~^~~~~~~~~~
boat.cpp:124:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int c = 0; c < T.size(); ++c) {
~~^~~~~~~~~~
boat.cpp:133:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (int c = 0; c + 1 < T.size(); ++c) {
~~~~~~^~~~~~~~~~
boat.cpp:66:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &n);
~~~~~^~~~~~~~~~
boat.cpp:69:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &arr[i].fi, &arr[i].se);
~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1168 ms |
12196 KB |
Output is correct |
2 |
Correct |
1190 ms |
12196 KB |
Output is correct |
3 |
Correct |
1196 ms |
12192 KB |
Output is correct |
4 |
Correct |
1191 ms |
12192 KB |
Output is correct |
5 |
Correct |
1240 ms |
12192 KB |
Output is correct |
6 |
Correct |
1106 ms |
12280 KB |
Output is correct |
7 |
Correct |
1104 ms |
12188 KB |
Output is correct |
8 |
Correct |
1078 ms |
12400 KB |
Output is correct |
9 |
Correct |
1106 ms |
12280 KB |
Output is correct |
10 |
Correct |
1109 ms |
12220 KB |
Output is correct |
11 |
Correct |
1062 ms |
12284 KB |
Output is correct |
12 |
Correct |
1081 ms |
12192 KB |
Output is correct |
13 |
Correct |
1114 ms |
12280 KB |
Output is correct |
14 |
Correct |
1100 ms |
12280 KB |
Output is correct |
15 |
Correct |
1137 ms |
12196 KB |
Output is correct |
16 |
Correct |
129 ms |
2424 KB |
Output is correct |
17 |
Correct |
137 ms |
2552 KB |
Output is correct |
18 |
Correct |
130 ms |
2552 KB |
Output is correct |
19 |
Correct |
145 ms |
2808 KB |
Output is correct |
20 |
Correct |
134 ms |
2552 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1168 ms |
12196 KB |
Output is correct |
2 |
Correct |
1190 ms |
12196 KB |
Output is correct |
3 |
Correct |
1196 ms |
12192 KB |
Output is correct |
4 |
Correct |
1191 ms |
12192 KB |
Output is correct |
5 |
Correct |
1240 ms |
12192 KB |
Output is correct |
6 |
Correct |
1106 ms |
12280 KB |
Output is correct |
7 |
Correct |
1104 ms |
12188 KB |
Output is correct |
8 |
Correct |
1078 ms |
12400 KB |
Output is correct |
9 |
Correct |
1106 ms |
12280 KB |
Output is correct |
10 |
Correct |
1109 ms |
12220 KB |
Output is correct |
11 |
Correct |
1062 ms |
12284 KB |
Output is correct |
12 |
Correct |
1081 ms |
12192 KB |
Output is correct |
13 |
Correct |
1114 ms |
12280 KB |
Output is correct |
14 |
Correct |
1100 ms |
12280 KB |
Output is correct |
15 |
Correct |
1137 ms |
12196 KB |
Output is correct |
16 |
Correct |
129 ms |
2424 KB |
Output is correct |
17 |
Correct |
137 ms |
2552 KB |
Output is correct |
18 |
Correct |
130 ms |
2552 KB |
Output is correct |
19 |
Correct |
145 ms |
2808 KB |
Output is correct |
20 |
Correct |
134 ms |
2552 KB |
Output is correct |
21 |
Correct |
1157 ms |
11256 KB |
Output is correct |
22 |
Correct |
1236 ms |
11328 KB |
Output is correct |
23 |
Correct |
1145 ms |
11128 KB |
Output is correct |
24 |
Correct |
1224 ms |
11012 KB |
Output is correct |
25 |
Correct |
1278 ms |
11064 KB |
Output is correct |
26 |
Correct |
1339 ms |
10776 KB |
Output is correct |
27 |
Correct |
1405 ms |
10944 KB |
Output is correct |
28 |
Correct |
1390 ms |
10768 KB |
Output is correct |
29 |
Correct |
1575 ms |
10724 KB |
Output is correct |
30 |
Correct |
1303 ms |
12164 KB |
Output is correct |
31 |
Correct |
1307 ms |
12180 KB |
Output is correct |
32 |
Correct |
1223 ms |
12168 KB |
Output is correct |
33 |
Correct |
1282 ms |
12176 KB |
Output is correct |
34 |
Correct |
1317 ms |
12144 KB |
Output is correct |
35 |
Correct |
1295 ms |
12156 KB |
Output is correct |
36 |
Correct |
1219 ms |
12168 KB |
Output is correct |
37 |
Correct |
1176 ms |
12152 KB |
Output is correct |
38 |
Correct |
1218 ms |
12064 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
19 ms |
2680 KB |
Output is correct |
2 |
Correct |
19 ms |
2680 KB |
Output is correct |
3 |
Correct |
26 ms |
2680 KB |
Output is correct |
4 |
Correct |
19 ms |
2680 KB |
Output is correct |
5 |
Correct |
20 ms |
2680 KB |
Output is correct |
6 |
Correct |
19 ms |
2680 KB |
Output is correct |
7 |
Correct |
20 ms |
2680 KB |
Output is correct |
8 |
Correct |
20 ms |
2680 KB |
Output is correct |
9 |
Correct |
20 ms |
2680 KB |
Output is correct |
10 |
Correct |
19 ms |
2680 KB |
Output is correct |
11 |
Correct |
19 ms |
2680 KB |
Output is correct |
12 |
Correct |
18 ms |
2680 KB |
Output is correct |
13 |
Correct |
19 ms |
2680 KB |
Output is correct |
14 |
Correct |
19 ms |
2680 KB |
Output is correct |
15 |
Correct |
19 ms |
2680 KB |
Output is correct |
16 |
Correct |
12 ms |
1656 KB |
Output is correct |
17 |
Correct |
12 ms |
1656 KB |
Output is correct |
18 |
Correct |
13 ms |
1656 KB |
Output is correct |
19 |
Correct |
12 ms |
1656 KB |
Output is correct |
20 |
Correct |
13 ms |
1656 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1168 ms |
12196 KB |
Output is correct |
2 |
Correct |
1190 ms |
12196 KB |
Output is correct |
3 |
Correct |
1196 ms |
12192 KB |
Output is correct |
4 |
Correct |
1191 ms |
12192 KB |
Output is correct |
5 |
Correct |
1240 ms |
12192 KB |
Output is correct |
6 |
Correct |
1106 ms |
12280 KB |
Output is correct |
7 |
Correct |
1104 ms |
12188 KB |
Output is correct |
8 |
Correct |
1078 ms |
12400 KB |
Output is correct |
9 |
Correct |
1106 ms |
12280 KB |
Output is correct |
10 |
Correct |
1109 ms |
12220 KB |
Output is correct |
11 |
Correct |
1062 ms |
12284 KB |
Output is correct |
12 |
Correct |
1081 ms |
12192 KB |
Output is correct |
13 |
Correct |
1114 ms |
12280 KB |
Output is correct |
14 |
Correct |
1100 ms |
12280 KB |
Output is correct |
15 |
Correct |
1137 ms |
12196 KB |
Output is correct |
16 |
Correct |
129 ms |
2424 KB |
Output is correct |
17 |
Correct |
137 ms |
2552 KB |
Output is correct |
18 |
Correct |
130 ms |
2552 KB |
Output is correct |
19 |
Correct |
145 ms |
2808 KB |
Output is correct |
20 |
Correct |
134 ms |
2552 KB |
Output is correct |
21 |
Correct |
1157 ms |
11256 KB |
Output is correct |
22 |
Correct |
1236 ms |
11328 KB |
Output is correct |
23 |
Correct |
1145 ms |
11128 KB |
Output is correct |
24 |
Correct |
1224 ms |
11012 KB |
Output is correct |
25 |
Correct |
1278 ms |
11064 KB |
Output is correct |
26 |
Correct |
1339 ms |
10776 KB |
Output is correct |
27 |
Correct |
1405 ms |
10944 KB |
Output is correct |
28 |
Correct |
1390 ms |
10768 KB |
Output is correct |
29 |
Correct |
1575 ms |
10724 KB |
Output is correct |
30 |
Correct |
1303 ms |
12164 KB |
Output is correct |
31 |
Correct |
1307 ms |
12180 KB |
Output is correct |
32 |
Correct |
1223 ms |
12168 KB |
Output is correct |
33 |
Correct |
1282 ms |
12176 KB |
Output is correct |
34 |
Correct |
1317 ms |
12144 KB |
Output is correct |
35 |
Correct |
1295 ms |
12156 KB |
Output is correct |
36 |
Correct |
1219 ms |
12168 KB |
Output is correct |
37 |
Correct |
1176 ms |
12152 KB |
Output is correct |
38 |
Correct |
1218 ms |
12064 KB |
Output is correct |
39 |
Correct |
19 ms |
2680 KB |
Output is correct |
40 |
Correct |
19 ms |
2680 KB |
Output is correct |
41 |
Correct |
26 ms |
2680 KB |
Output is correct |
42 |
Correct |
19 ms |
2680 KB |
Output is correct |
43 |
Correct |
20 ms |
2680 KB |
Output is correct |
44 |
Correct |
19 ms |
2680 KB |
Output is correct |
45 |
Correct |
20 ms |
2680 KB |
Output is correct |
46 |
Correct |
20 ms |
2680 KB |
Output is correct |
47 |
Correct |
20 ms |
2680 KB |
Output is correct |
48 |
Correct |
19 ms |
2680 KB |
Output is correct |
49 |
Correct |
19 ms |
2680 KB |
Output is correct |
50 |
Correct |
18 ms |
2680 KB |
Output is correct |
51 |
Correct |
19 ms |
2680 KB |
Output is correct |
52 |
Correct |
19 ms |
2680 KB |
Output is correct |
53 |
Correct |
19 ms |
2680 KB |
Output is correct |
54 |
Correct |
12 ms |
1656 KB |
Output is correct |
55 |
Correct |
12 ms |
1656 KB |
Output is correct |
56 |
Correct |
13 ms |
1656 KB |
Output is correct |
57 |
Correct |
12 ms |
1656 KB |
Output is correct |
58 |
Correct |
13 ms |
1656 KB |
Output is correct |
59 |
Correct |
1532 ms |
12164 KB |
Output is correct |
60 |
Correct |
1449 ms |
12280 KB |
Output is correct |
61 |
Correct |
1396 ms |
12280 KB |
Output is correct |
62 |
Correct |
1913 ms |
12320 KB |
Output is correct |
63 |
Correct |
1455 ms |
12152 KB |
Output is correct |
64 |
Correct |
1755 ms |
12192 KB |
Output is correct |
65 |
Correct |
1706 ms |
12188 KB |
Output is correct |
66 |
Correct |
1733 ms |
12192 KB |
Output is correct |
67 |
Correct |
1742 ms |
12192 KB |
Output is correct |
68 |
Correct |
1688 ms |
12200 KB |
Output is correct |
69 |
Correct |
1591 ms |
12200 KB |
Output is correct |
70 |
Correct |
1531 ms |
12196 KB |
Output is correct |
71 |
Correct |
1638 ms |
12200 KB |
Output is correct |
72 |
Correct |
1687 ms |
12216 KB |
Output is correct |
73 |
Correct |
1816 ms |
12188 KB |
Output is correct |
74 |
Correct |
192 ms |
2424 KB |
Output is correct |
75 |
Correct |
198 ms |
2552 KB |
Output is correct |
76 |
Correct |
195 ms |
2552 KB |
Output is correct |
77 |
Correct |
209 ms |
2552 KB |
Output is correct |
78 |
Correct |
193 ms |
2552 KB |
Output is correct |