#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=0;j<=n;j++){
D[i][j] = ncr(v[i]-v[i-1], j);
}
}
for(int i=1;i<v.size();i++){
for(int j=1;j<=n;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=l[i];j<=r[i];j++){
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;
}
}
for(int j=1;j<v.size();j++){
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:51:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=1;i<v.size();i++){
~^~~~~~~~~
boat.cpp:56:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=1;i<v.size();i++){
~^~~~~~~~~
boat.cpp:74:22: 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 |
1172 ms |
10200 KB |
Output is correct |
2 |
Correct |
1171 ms |
10228 KB |
Output is correct |
3 |
Correct |
1183 ms |
10172 KB |
Output is correct |
4 |
Correct |
1190 ms |
10344 KB |
Output is correct |
5 |
Correct |
1177 ms |
10300 KB |
Output is correct |
6 |
Correct |
1183 ms |
10448 KB |
Output is correct |
7 |
Correct |
1169 ms |
10232 KB |
Output is correct |
8 |
Correct |
1175 ms |
10296 KB |
Output is correct |
9 |
Correct |
1220 ms |
10220 KB |
Output is correct |
10 |
Correct |
1312 ms |
10260 KB |
Output is correct |
11 |
Correct |
1194 ms |
10360 KB |
Output is correct |
12 |
Correct |
1185 ms |
10268 KB |
Output is correct |
13 |
Correct |
1177 ms |
10164 KB |
Output is correct |
14 |
Correct |
1170 ms |
10160 KB |
Output is correct |
15 |
Correct |
1174 ms |
10268 KB |
Output is correct |
16 |
Correct |
216 ms |
6904 KB |
Output is correct |
17 |
Correct |
231 ms |
7060 KB |
Output is correct |
18 |
Correct |
225 ms |
6904 KB |
Output is correct |
19 |
Correct |
230 ms |
7020 KB |
Output is correct |
20 |
Correct |
222 ms |
6928 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1172 ms |
10200 KB |
Output is correct |
2 |
Correct |
1171 ms |
10228 KB |
Output is correct |
3 |
Correct |
1183 ms |
10172 KB |
Output is correct |
4 |
Correct |
1190 ms |
10344 KB |
Output is correct |
5 |
Correct |
1177 ms |
10300 KB |
Output is correct |
6 |
Correct |
1183 ms |
10448 KB |
Output is correct |
7 |
Correct |
1169 ms |
10232 KB |
Output is correct |
8 |
Correct |
1175 ms |
10296 KB |
Output is correct |
9 |
Correct |
1220 ms |
10220 KB |
Output is correct |
10 |
Correct |
1312 ms |
10260 KB |
Output is correct |
11 |
Correct |
1194 ms |
10360 KB |
Output is correct |
12 |
Correct |
1185 ms |
10268 KB |
Output is correct |
13 |
Correct |
1177 ms |
10164 KB |
Output is correct |
14 |
Correct |
1170 ms |
10160 KB |
Output is correct |
15 |
Correct |
1174 ms |
10268 KB |
Output is correct |
16 |
Correct |
216 ms |
6904 KB |
Output is correct |
17 |
Correct |
231 ms |
7060 KB |
Output is correct |
18 |
Correct |
225 ms |
6904 KB |
Output is correct |
19 |
Correct |
230 ms |
7020 KB |
Output is correct |
20 |
Correct |
222 ms |
6928 KB |
Output is correct |
21 |
Correct |
947 ms |
9996 KB |
Output is correct |
22 |
Correct |
956 ms |
9912 KB |
Output is correct |
23 |
Correct |
938 ms |
9948 KB |
Output is correct |
24 |
Correct |
961 ms |
9808 KB |
Output is correct |
25 |
Correct |
940 ms |
9976 KB |
Output is correct |
26 |
Correct |
1012 ms |
9804 KB |
Output is correct |
27 |
Correct |
1046 ms |
9696 KB |
Output is correct |
28 |
Correct |
1000 ms |
9720 KB |
Output is correct |
29 |
Correct |
1090 ms |
9864 KB |
Output is correct |
30 |
Correct |
1119 ms |
10360 KB |
Output is correct |
31 |
Correct |
1115 ms |
10244 KB |
Output is correct |
32 |
Correct |
1120 ms |
10256 KB |
Output is correct |
33 |
Correct |
1131 ms |
10264 KB |
Output is correct |
34 |
Correct |
1108 ms |
10176 KB |
Output is correct |
35 |
Correct |
1124 ms |
10220 KB |
Output is correct |
36 |
Correct |
1097 ms |
10360 KB |
Output is correct |
37 |
Correct |
1130 ms |
10248 KB |
Output is correct |
38 |
Correct |
1102 ms |
10416 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
22 ms |
5496 KB |
Output is correct |
2 |
Correct |
23 ms |
5496 KB |
Output is correct |
3 |
Correct |
22 ms |
5496 KB |
Output is correct |
4 |
Correct |
22 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 |
24 ms |
5496 KB |
Output is correct |
8 |
Correct |
23 ms |
5496 KB |
Output is correct |
9 |
Correct |
23 ms |
5456 KB |
Output is correct |
10 |
Correct |
23 ms |
5500 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 |
5496 KB |
Output is correct |
14 |
Correct |
22 ms |
5496 KB |
Output is correct |
15 |
Correct |
22 ms |
5496 KB |
Output is correct |
16 |
Correct |
16 ms |
5112 KB |
Output is correct |
17 |
Correct |
15 ms |
5112 KB |
Output is correct |
18 |
Correct |
17 ms |
5112 KB |
Output is correct |
19 |
Correct |
16 ms |
5112 KB |
Output is correct |
20 |
Correct |
15 ms |
5112 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1172 ms |
10200 KB |
Output is correct |
2 |
Correct |
1171 ms |
10228 KB |
Output is correct |
3 |
Correct |
1183 ms |
10172 KB |
Output is correct |
4 |
Correct |
1190 ms |
10344 KB |
Output is correct |
5 |
Correct |
1177 ms |
10300 KB |
Output is correct |
6 |
Correct |
1183 ms |
10448 KB |
Output is correct |
7 |
Correct |
1169 ms |
10232 KB |
Output is correct |
8 |
Correct |
1175 ms |
10296 KB |
Output is correct |
9 |
Correct |
1220 ms |
10220 KB |
Output is correct |
10 |
Correct |
1312 ms |
10260 KB |
Output is correct |
11 |
Correct |
1194 ms |
10360 KB |
Output is correct |
12 |
Correct |
1185 ms |
10268 KB |
Output is correct |
13 |
Correct |
1177 ms |
10164 KB |
Output is correct |
14 |
Correct |
1170 ms |
10160 KB |
Output is correct |
15 |
Correct |
1174 ms |
10268 KB |
Output is correct |
16 |
Correct |
216 ms |
6904 KB |
Output is correct |
17 |
Correct |
231 ms |
7060 KB |
Output is correct |
18 |
Correct |
225 ms |
6904 KB |
Output is correct |
19 |
Correct |
230 ms |
7020 KB |
Output is correct |
20 |
Correct |
222 ms |
6928 KB |
Output is correct |
21 |
Correct |
947 ms |
9996 KB |
Output is correct |
22 |
Correct |
956 ms |
9912 KB |
Output is correct |
23 |
Correct |
938 ms |
9948 KB |
Output is correct |
24 |
Correct |
961 ms |
9808 KB |
Output is correct |
25 |
Correct |
940 ms |
9976 KB |
Output is correct |
26 |
Correct |
1012 ms |
9804 KB |
Output is correct |
27 |
Correct |
1046 ms |
9696 KB |
Output is correct |
28 |
Correct |
1000 ms |
9720 KB |
Output is correct |
29 |
Correct |
1090 ms |
9864 KB |
Output is correct |
30 |
Correct |
1119 ms |
10360 KB |
Output is correct |
31 |
Correct |
1115 ms |
10244 KB |
Output is correct |
32 |
Correct |
1120 ms |
10256 KB |
Output is correct |
33 |
Correct |
1131 ms |
10264 KB |
Output is correct |
34 |
Correct |
1108 ms |
10176 KB |
Output is correct |
35 |
Correct |
1124 ms |
10220 KB |
Output is correct |
36 |
Correct |
1097 ms |
10360 KB |
Output is correct |
37 |
Correct |
1130 ms |
10248 KB |
Output is correct |
38 |
Correct |
1102 ms |
10416 KB |
Output is correct |
39 |
Correct |
22 ms |
5496 KB |
Output is correct |
40 |
Correct |
23 ms |
5496 KB |
Output is correct |
41 |
Correct |
22 ms |
5496 KB |
Output is correct |
42 |
Correct |
22 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 |
24 ms |
5496 KB |
Output is correct |
46 |
Correct |
23 ms |
5496 KB |
Output is correct |
47 |
Correct |
23 ms |
5456 KB |
Output is correct |
48 |
Correct |
23 ms |
5500 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 |
5496 KB |
Output is correct |
52 |
Correct |
22 ms |
5496 KB |
Output is correct |
53 |
Correct |
22 ms |
5496 KB |
Output is correct |
54 |
Correct |
16 ms |
5112 KB |
Output is correct |
55 |
Correct |
15 ms |
5112 KB |
Output is correct |
56 |
Correct |
17 ms |
5112 KB |
Output is correct |
57 |
Correct |
16 ms |
5112 KB |
Output is correct |
58 |
Correct |
15 ms |
5112 KB |
Output is correct |
59 |
Correct |
1950 ms |
10232 KB |
Output is correct |
60 |
Correct |
1899 ms |
10372 KB |
Output is correct |
61 |
Correct |
1851 ms |
10188 KB |
Output is correct |
62 |
Execution timed out |
2049 ms |
9996 KB |
Time limit exceeded |
63 |
Halted |
0 ms |
0 KB |
- |