#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9+7;
int binPow(int a, int b){
int ans = 1;
while(b){
if(b%2 == 1) ans = ans*1ll*a%mod;
a = a*1ll*a%mod;
b/=2;
}
return ans;
}
int f[1001], inv[1001], a[501], b[501], l[501], r[501];
int ncr(int a, int b){
if(b > a) return 0;
int mn = min(a-b, b), mx = max(a-b, b);
int ans = 1;
for(int i=a;i>mx;i--) ans = (ans*1ll*i)%mod;
return ans*1ll*inv[mn]%mod;
}
int dp[501][1001];
int D[1001][501], C[1001][1001];
int sum[1001][501];
int main(){
C[0][0] = 1;
for(int i=1;i<=1000;i++){
C[i][0] = C[i][i] = 1;
for(int j=1;j<i;j++){
C[i][j] = (C[i-1][j] + C[i-1][j-1])%mod;
}
}
f[0] = 1;
for(int i=1;i<=1000;i++) f[i] = f[i-1]*1ll*i%mod;
for(int i=0;i<=1000;i++) inv[i] = binPow(f[i], mod-2);
int n;
scanf("%d", &n);
vector<int> v;
for(int i=1;i<=n;i++){
scanf("%d%d", &a[i], &b[i]);
v.push_back(a[i]-1);
v.push_back(b[i]);
}
sort(v.begin(), v.end());
v.erase(unique(v.begin(), v.end()), v.end());
for(int i=1;i<=n;i++){
l[i] = lower_bound(v.begin(), v.end(), a[i]) - v.begin();
r[i] = lower_bound(v.begin(), v.end(), b[i]) - v.begin();
}
// for(int i=1;i<v.size();i++){
// for(int j=1;j<=n;j++){
// D[i][j] = ncr(v[i]-v[i-1], j);
// for(int l=0;l<j;l++){
// sum[i][j] = (sum[i][j] + D[i][l+1]*1ll*C[j-1][l])%mod;
// }
// }
// }
for(int j=0;j<=1000;j++) dp[0][j] = 1;
int ans = 0;
for(int i=1;i<=n;i++){
for(int j=1;j<v.size();j++){
D[j][i] = ncr(v[j]-v[j-1], i);
for(int l=0;l<i;l++){
sum[j][i] = (sum[j][i] + D[j][l+1]*1ll*C[i-1][l])%mod;
}
if(l[i] <= j && j <= r[i]){
int cnt = 0;
for(int k=i;k>=1;k--){
if(l[k] <= j && j <= r[k]) cnt++;
dp[i][j] = (dp[i][j] + dp[k-1][j-1]*1ll*sum[j][cnt])%mod;
}
}
dp[i][j] = (dp[i][j] + dp[i][j-1])%mod;
}
ans = (ans + dp[i][v.size()-1])%mod;
}
printf("%d\n", ans);
}
Compilation message
boat.cpp: In function 'int main()':
boat.cpp:62:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=1;j<v.size();j++){
~^~~~~~~~~
boat.cpp:37:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &n);
~~~~~^~~~~~~~~~
boat.cpp:41:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &a[i], &b[i]);
~~~~~^~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1198 ms |
10252 KB |
Output is correct |
2 |
Correct |
1278 ms |
10260 KB |
Output is correct |
3 |
Correct |
1241 ms |
10260 KB |
Output is correct |
4 |
Correct |
1203 ms |
10232 KB |
Output is correct |
5 |
Correct |
1224 ms |
10196 KB |
Output is correct |
6 |
Correct |
1267 ms |
10176 KB |
Output is correct |
7 |
Correct |
1226 ms |
10284 KB |
Output is correct |
8 |
Correct |
1192 ms |
10268 KB |
Output is correct |
9 |
Correct |
1219 ms |
10396 KB |
Output is correct |
10 |
Correct |
1216 ms |
10208 KB |
Output is correct |
11 |
Correct |
1200 ms |
10116 KB |
Output is correct |
12 |
Correct |
1211 ms |
10232 KB |
Output is correct |
13 |
Correct |
1211 ms |
10272 KB |
Output is correct |
14 |
Correct |
1195 ms |
10132 KB |
Output is correct |
15 |
Correct |
1184 ms |
10264 KB |
Output is correct |
16 |
Correct |
215 ms |
6972 KB |
Output is correct |
17 |
Correct |
229 ms |
6988 KB |
Output is correct |
18 |
Correct |
232 ms |
6908 KB |
Output is correct |
19 |
Correct |
229 ms |
7060 KB |
Output is correct |
20 |
Correct |
222 ms |
6904 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1198 ms |
10252 KB |
Output is correct |
2 |
Correct |
1278 ms |
10260 KB |
Output is correct |
3 |
Correct |
1241 ms |
10260 KB |
Output is correct |
4 |
Correct |
1203 ms |
10232 KB |
Output is correct |
5 |
Correct |
1224 ms |
10196 KB |
Output is correct |
6 |
Correct |
1267 ms |
10176 KB |
Output is correct |
7 |
Correct |
1226 ms |
10284 KB |
Output is correct |
8 |
Correct |
1192 ms |
10268 KB |
Output is correct |
9 |
Correct |
1219 ms |
10396 KB |
Output is correct |
10 |
Correct |
1216 ms |
10208 KB |
Output is correct |
11 |
Correct |
1200 ms |
10116 KB |
Output is correct |
12 |
Correct |
1211 ms |
10232 KB |
Output is correct |
13 |
Correct |
1211 ms |
10272 KB |
Output is correct |
14 |
Correct |
1195 ms |
10132 KB |
Output is correct |
15 |
Correct |
1184 ms |
10264 KB |
Output is correct |
16 |
Correct |
215 ms |
6972 KB |
Output is correct |
17 |
Correct |
229 ms |
6988 KB |
Output is correct |
18 |
Correct |
232 ms |
6908 KB |
Output is correct |
19 |
Correct |
229 ms |
7060 KB |
Output is correct |
20 |
Correct |
222 ms |
6904 KB |
Output is correct |
21 |
Correct |
1052 ms |
9832 KB |
Output is correct |
22 |
Correct |
1051 ms |
10152 KB |
Output is correct |
23 |
Correct |
1014 ms |
10008 KB |
Output is correct |
24 |
Correct |
1065 ms |
9884 KB |
Output is correct |
25 |
Correct |
998 ms |
9860 KB |
Output is correct |
26 |
Correct |
1049 ms |
9880 KB |
Output is correct |
27 |
Correct |
1081 ms |
9976 KB |
Output is correct |
28 |
Correct |
1069 ms |
9672 KB |
Output is correct |
29 |
Correct |
1037 ms |
9776 KB |
Output is correct |
30 |
Correct |
1133 ms |
10260 KB |
Output is correct |
31 |
Correct |
1122 ms |
10100 KB |
Output is correct |
32 |
Correct |
1139 ms |
10332 KB |
Output is correct |
33 |
Correct |
1282 ms |
10236 KB |
Output is correct |
34 |
Correct |
1132 ms |
10212 KB |
Output is correct |
35 |
Correct |
1141 ms |
10164 KB |
Output is correct |
36 |
Correct |
1111 ms |
10348 KB |
Output is correct |
37 |
Correct |
1129 ms |
10232 KB |
Output is correct |
38 |
Correct |
1155 ms |
10088 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
22 ms |
5368 KB |
Output is correct |
2 |
Correct |
23 ms |
5496 KB |
Output is correct |
3 |
Correct |
22 ms |
5496 KB |
Output is correct |
4 |
Correct |
23 ms |
5496 KB |
Output is correct |
5 |
Correct |
23 ms |
5496 KB |
Output is correct |
6 |
Correct |
23 ms |
5496 KB |
Output is correct |
7 |
Correct |
23 ms |
5496 KB |
Output is correct |
8 |
Correct |
23 ms |
5496 KB |
Output is correct |
9 |
Correct |
23 ms |
5496 KB |
Output is correct |
10 |
Correct |
23 ms |
5496 KB |
Output is correct |
11 |
Correct |
23 ms |
5496 KB |
Output is correct |
12 |
Correct |
22 ms |
5496 KB |
Output is correct |
13 |
Correct |
22 ms |
5368 KB |
Output is correct |
14 |
Correct |
22 ms |
5496 KB |
Output is correct |
15 |
Correct |
22 ms |
5368 KB |
Output is correct |
16 |
Correct |
23 ms |
5112 KB |
Output is correct |
17 |
Correct |
15 ms |
5084 KB |
Output is correct |
18 |
Correct |
14 ms |
5112 KB |
Output is correct |
19 |
Correct |
15 ms |
5112 KB |
Output is correct |
20 |
Correct |
15 ms |
5112 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1198 ms |
10252 KB |
Output is correct |
2 |
Correct |
1278 ms |
10260 KB |
Output is correct |
3 |
Correct |
1241 ms |
10260 KB |
Output is correct |
4 |
Correct |
1203 ms |
10232 KB |
Output is correct |
5 |
Correct |
1224 ms |
10196 KB |
Output is correct |
6 |
Correct |
1267 ms |
10176 KB |
Output is correct |
7 |
Correct |
1226 ms |
10284 KB |
Output is correct |
8 |
Correct |
1192 ms |
10268 KB |
Output is correct |
9 |
Correct |
1219 ms |
10396 KB |
Output is correct |
10 |
Correct |
1216 ms |
10208 KB |
Output is correct |
11 |
Correct |
1200 ms |
10116 KB |
Output is correct |
12 |
Correct |
1211 ms |
10232 KB |
Output is correct |
13 |
Correct |
1211 ms |
10272 KB |
Output is correct |
14 |
Correct |
1195 ms |
10132 KB |
Output is correct |
15 |
Correct |
1184 ms |
10264 KB |
Output is correct |
16 |
Correct |
215 ms |
6972 KB |
Output is correct |
17 |
Correct |
229 ms |
6988 KB |
Output is correct |
18 |
Correct |
232 ms |
6908 KB |
Output is correct |
19 |
Correct |
229 ms |
7060 KB |
Output is correct |
20 |
Correct |
222 ms |
6904 KB |
Output is correct |
21 |
Correct |
1052 ms |
9832 KB |
Output is correct |
22 |
Correct |
1051 ms |
10152 KB |
Output is correct |
23 |
Correct |
1014 ms |
10008 KB |
Output is correct |
24 |
Correct |
1065 ms |
9884 KB |
Output is correct |
25 |
Correct |
998 ms |
9860 KB |
Output is correct |
26 |
Correct |
1049 ms |
9880 KB |
Output is correct |
27 |
Correct |
1081 ms |
9976 KB |
Output is correct |
28 |
Correct |
1069 ms |
9672 KB |
Output is correct |
29 |
Correct |
1037 ms |
9776 KB |
Output is correct |
30 |
Correct |
1133 ms |
10260 KB |
Output is correct |
31 |
Correct |
1122 ms |
10100 KB |
Output is correct |
32 |
Correct |
1139 ms |
10332 KB |
Output is correct |
33 |
Correct |
1282 ms |
10236 KB |
Output is correct |
34 |
Correct |
1132 ms |
10212 KB |
Output is correct |
35 |
Correct |
1141 ms |
10164 KB |
Output is correct |
36 |
Correct |
1111 ms |
10348 KB |
Output is correct |
37 |
Correct |
1129 ms |
10232 KB |
Output is correct |
38 |
Correct |
1155 ms |
10088 KB |
Output is correct |
39 |
Correct |
22 ms |
5368 KB |
Output is correct |
40 |
Correct |
23 ms |
5496 KB |
Output is correct |
41 |
Correct |
22 ms |
5496 KB |
Output is correct |
42 |
Correct |
23 ms |
5496 KB |
Output is correct |
43 |
Correct |
23 ms |
5496 KB |
Output is correct |
44 |
Correct |
23 ms |
5496 KB |
Output is correct |
45 |
Correct |
23 ms |
5496 KB |
Output is correct |
46 |
Correct |
23 ms |
5496 KB |
Output is correct |
47 |
Correct |
23 ms |
5496 KB |
Output is correct |
48 |
Correct |
23 ms |
5496 KB |
Output is correct |
49 |
Correct |
23 ms |
5496 KB |
Output is correct |
50 |
Correct |
22 ms |
5496 KB |
Output is correct |
51 |
Correct |
22 ms |
5368 KB |
Output is correct |
52 |
Correct |
22 ms |
5496 KB |
Output is correct |
53 |
Correct |
22 ms |
5368 KB |
Output is correct |
54 |
Correct |
23 ms |
5112 KB |
Output is correct |
55 |
Correct |
15 ms |
5084 KB |
Output is correct |
56 |
Correct |
14 ms |
5112 KB |
Output is correct |
57 |
Correct |
15 ms |
5112 KB |
Output is correct |
58 |
Correct |
15 ms |
5112 KB |
Output is correct |
59 |
Execution timed out |
2044 ms |
10188 KB |
Time limit exceeded |
60 |
Halted |
0 ms |
0 KB |
- |