#include <bits/stdc++.h>
using namespace std;
typedef pair<long long, long long> ii;
long long mod = 1000000007;
//long long dp[505][2005];
//static long long dp[505][2005][505];
#define int long long
long long modInverse(long long a, long long m)
{
long long m0 = m;
long long y = 0, x = 1;
if (m == 1)
return 0;
while (a > 1)
{
// q is quotient
long long q = a / m;
long long t = m;
// m is remainder now, process same as
// Euclid's algo
m = a % m, a = t;
t = y;
// Update y and x
y = x - q * y;
x = t;
}
// Make x positive
if (x < 0)
x += m0;
return x;
}
main()
{
//freopen("i.txt","r",stdin);
ios_base::sync_with_stdio(false);
long long inverse[505];
for(long long i = 1;i < 505;i++){
inverse[i] = modInverse(i,mod);
}
int n;
cin >> n;
long long a[n];
long long b[n];
set<long long> s;
for(int i = 0;i < n;i++){
cin >> a[i] >> b[i];
s.insert(a[i]);
s.insert(b[i]+1);
}
//cout << s.size() << endl;
vector<long long> key;
for(set<long long>::iterator it = s.begin();it != s.end();it++){
key.push_back(*it);
}
//cout << k.size() << endl;
vector<ii> ranges;
for(int i = 0;i < key.size();i++){
//ranges.push_back(ii(key[i],key[i]));
if(i != 0){
//if(key[i] != key[i-1]+1){
ranges.push_back(ii(key[i-1],key[i]-1));
//}
}
}
sort(ranges.begin(),ranges.end());
int m = ranges.size();
//cout << m << "\n";
long long diff[m];
for(int i = 0;i < m;i++){
diff[i] = ranges[i].second - ranges[i].first + 1;
diff[i] %= mod;
//cout << ranges[i].first << " " << ranges[i].second << "\n";
}
long long posa[n];
long long posb[n];
for(int i = 0;i < n;i++){
for(int j = 0;j < m;j++){
if(ranges[j].first == a[i]) posa[i] = j;
if(ranges[j].second == b[i]) posb[i] = j;
}
}
static long long dp[2][2005][505];
//boat no, range, number taken b4;
for(int i = 0;i < 2;i++){
for(int j = 0;j < m;j++){
for(int k = 0;k < 505;k++){
dp[i][j][k] = 0ll;
}
}
}
for(int j = posa[0];j <= posb[0];j++){
if(a[0] <= ranges[j].first && b[0] >= ranges[j].second){
dp[0][j][1] = diff[j];
//cout << a[0] << " " << ranges[j].first << " " << ranges[j].second << " " << b[0] << endl;
}
}
for(int i = 1;i < n;i++){
///take nothing for this school
int ii = i % 2;
for(int j = 0;j < m;j++){
for(int k = 1;k < 505;k++){
if(dp[ii^1][j][k] == 0) break;
dp[ii][j][k] = dp[ii^1][j][k];
dp[ii][j][k] %= mod;
}
}
///take same as previous school
for(int j = posa[i];j <= posb[i];j++){
if(a[i] <= ranges[j].first && b[i] >= ranges[j].second){
for(int k = 2;k < 505;k++){
long long x = dp[ii^1][j][k-1];
if(diff[j] - k + 1 <= 0) break;
x *= (diff[j] - k + 1);
x %= mod;
x *= inverse[k];
x %= mod;
//dp[ii][j][k] = dp[ii^1][j][k];
dp[ii][j][k] += x;
//dp[ii][j][k] %= mod;
}
}
}
///take for the first time
long long acc = 0ll;
for(int j = 0;j < m;j++){
if(j != 0){
for(int k = 1;k < 505;k++){
if(dp[ii^1][j-1][k] == 0) break;
acc += dp[ii^1][j-1][k];
acc %= mod;
}
}
if(a[i] <= ranges[j].first && b[i] >= ranges[j].second){
long long x = acc;
x += 1;
x *= diff[j];
acc %= mod;
//dp[ii][j][1] = dp[ii^1][j][1];
dp[ii][j][1] += x;
dp[ii][j][1] %= mod;
}
}
}
/*
for(int j = 0;j < m;j++){
cout << ranges[j].first << " " << ranges[j].second << ": ";
for(int i = 0;i < n;i++){
cout << dp[i][j] << " ";
}
cout << "\n";
}
*/
long long ans = 0ll;
for(int j = 0;j < m;j++){
for(int k = 1;k < 505;k++){
ans += dp[(n-1)%2][j][k];
ans %= mod;
if(dp[(n-1)%2][j][k] != 0){
//cout << j << " " << k << " " << dp[(n-1)%2][j][k] << "\n";
}
}
}
cout << ans;
return 0;
}
Compilation message
boat.cpp:39:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
main()
^
boat.cpp: In function 'int main()':
boat.cpp:65:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0;i < key.size();i++){
~~^~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
29 ms |
8440 KB |
Output is correct |
2 |
Correct |
25 ms |
8440 KB |
Output is correct |
3 |
Correct |
24 ms |
8312 KB |
Output is correct |
4 |
Correct |
25 ms |
8440 KB |
Output is correct |
5 |
Correct |
25 ms |
8312 KB |
Output is correct |
6 |
Correct |
24 ms |
8312 KB |
Output is correct |
7 |
Correct |
25 ms |
8316 KB |
Output is correct |
8 |
Correct |
23 ms |
8440 KB |
Output is correct |
9 |
Correct |
26 ms |
8540 KB |
Output is correct |
10 |
Correct |
23 ms |
8440 KB |
Output is correct |
11 |
Correct |
23 ms |
8312 KB |
Output is correct |
12 |
Correct |
22 ms |
8440 KB |
Output is correct |
13 |
Correct |
23 ms |
8440 KB |
Output is correct |
14 |
Correct |
23 ms |
8312 KB |
Output is correct |
15 |
Correct |
22 ms |
8312 KB |
Output is correct |
16 |
Correct |
6 ms |
1784 KB |
Output is correct |
17 |
Correct |
6 ms |
1912 KB |
Output is correct |
18 |
Correct |
7 ms |
1784 KB |
Output is correct |
19 |
Correct |
6 ms |
1912 KB |
Output is correct |
20 |
Correct |
6 ms |
1912 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
29 ms |
8440 KB |
Output is correct |
2 |
Correct |
25 ms |
8440 KB |
Output is correct |
3 |
Correct |
24 ms |
8312 KB |
Output is correct |
4 |
Correct |
25 ms |
8440 KB |
Output is correct |
5 |
Correct |
25 ms |
8312 KB |
Output is correct |
6 |
Correct |
24 ms |
8312 KB |
Output is correct |
7 |
Correct |
25 ms |
8316 KB |
Output is correct |
8 |
Correct |
23 ms |
8440 KB |
Output is correct |
9 |
Correct |
26 ms |
8540 KB |
Output is correct |
10 |
Correct |
23 ms |
8440 KB |
Output is correct |
11 |
Correct |
23 ms |
8312 KB |
Output is correct |
12 |
Correct |
22 ms |
8440 KB |
Output is correct |
13 |
Correct |
23 ms |
8440 KB |
Output is correct |
14 |
Correct |
23 ms |
8312 KB |
Output is correct |
15 |
Correct |
22 ms |
8312 KB |
Output is correct |
16 |
Correct |
6 ms |
1784 KB |
Output is correct |
17 |
Correct |
6 ms |
1912 KB |
Output is correct |
18 |
Correct |
7 ms |
1784 KB |
Output is correct |
19 |
Correct |
6 ms |
1912 KB |
Output is correct |
20 |
Correct |
6 ms |
1912 KB |
Output is correct |
21 |
Correct |
118 ms |
7748 KB |
Output is correct |
22 |
Correct |
127 ms |
7800 KB |
Output is correct |
23 |
Correct |
119 ms |
7544 KB |
Output is correct |
24 |
Correct |
120 ms |
7544 KB |
Output is correct |
25 |
Correct |
121 ms |
7772 KB |
Output is correct |
26 |
Correct |
94 ms |
7416 KB |
Output is correct |
27 |
Correct |
93 ms |
7672 KB |
Output is correct |
28 |
Correct |
89 ms |
7416 KB |
Output is correct |
29 |
Correct |
90 ms |
7412 KB |
Output is correct |
30 |
Correct |
37 ms |
8312 KB |
Output is correct |
31 |
Correct |
40 ms |
8312 KB |
Output is correct |
32 |
Correct |
36 ms |
8312 KB |
Output is correct |
33 |
Correct |
36 ms |
8312 KB |
Output is correct |
34 |
Correct |
36 ms |
8312 KB |
Output is correct |
35 |
Correct |
37 ms |
8312 KB |
Output is correct |
36 |
Correct |
45 ms |
8312 KB |
Output is correct |
37 |
Correct |
36 ms |
8312 KB |
Output is correct |
38 |
Correct |
35 ms |
8312 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
94 ms |
2000 KB |
Output is correct |
2 |
Correct |
106 ms |
2040 KB |
Output is correct |
3 |
Correct |
82 ms |
2084 KB |
Output is correct |
4 |
Correct |
84 ms |
1912 KB |
Output is correct |
5 |
Correct |
92 ms |
2012 KB |
Output is correct |
6 |
Correct |
123 ms |
2040 KB |
Output is correct |
7 |
Correct |
125 ms |
2040 KB |
Output is correct |
8 |
Correct |
127 ms |
2028 KB |
Output is correct |
9 |
Correct |
127 ms |
2004 KB |
Output is correct |
10 |
Correct |
129 ms |
1912 KB |
Output is correct |
11 |
Correct |
93 ms |
2036 KB |
Output is correct |
12 |
Correct |
76 ms |
1996 KB |
Output is correct |
13 |
Correct |
85 ms |
2040 KB |
Output is correct |
14 |
Correct |
82 ms |
1912 KB |
Output is correct |
15 |
Correct |
86 ms |
1912 KB |
Output is correct |
16 |
Correct |
41 ms |
1276 KB |
Output is correct |
17 |
Correct |
35 ms |
1272 KB |
Output is correct |
18 |
Correct |
38 ms |
1400 KB |
Output is correct |
19 |
Correct |
35 ms |
1312 KB |
Output is correct |
20 |
Correct |
42 ms |
1272 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
29 ms |
8440 KB |
Output is correct |
2 |
Correct |
25 ms |
8440 KB |
Output is correct |
3 |
Correct |
24 ms |
8312 KB |
Output is correct |
4 |
Correct |
25 ms |
8440 KB |
Output is correct |
5 |
Correct |
25 ms |
8312 KB |
Output is correct |
6 |
Correct |
24 ms |
8312 KB |
Output is correct |
7 |
Correct |
25 ms |
8316 KB |
Output is correct |
8 |
Correct |
23 ms |
8440 KB |
Output is correct |
9 |
Correct |
26 ms |
8540 KB |
Output is correct |
10 |
Correct |
23 ms |
8440 KB |
Output is correct |
11 |
Correct |
23 ms |
8312 KB |
Output is correct |
12 |
Correct |
22 ms |
8440 KB |
Output is correct |
13 |
Correct |
23 ms |
8440 KB |
Output is correct |
14 |
Correct |
23 ms |
8312 KB |
Output is correct |
15 |
Correct |
22 ms |
8312 KB |
Output is correct |
16 |
Correct |
6 ms |
1784 KB |
Output is correct |
17 |
Correct |
6 ms |
1912 KB |
Output is correct |
18 |
Correct |
7 ms |
1784 KB |
Output is correct |
19 |
Correct |
6 ms |
1912 KB |
Output is correct |
20 |
Correct |
6 ms |
1912 KB |
Output is correct |
21 |
Correct |
118 ms |
7748 KB |
Output is correct |
22 |
Correct |
127 ms |
7800 KB |
Output is correct |
23 |
Correct |
119 ms |
7544 KB |
Output is correct |
24 |
Correct |
120 ms |
7544 KB |
Output is correct |
25 |
Correct |
121 ms |
7772 KB |
Output is correct |
26 |
Correct |
94 ms |
7416 KB |
Output is correct |
27 |
Correct |
93 ms |
7672 KB |
Output is correct |
28 |
Correct |
89 ms |
7416 KB |
Output is correct |
29 |
Correct |
90 ms |
7412 KB |
Output is correct |
30 |
Correct |
37 ms |
8312 KB |
Output is correct |
31 |
Correct |
40 ms |
8312 KB |
Output is correct |
32 |
Correct |
36 ms |
8312 KB |
Output is correct |
33 |
Correct |
36 ms |
8312 KB |
Output is correct |
34 |
Correct |
36 ms |
8312 KB |
Output is correct |
35 |
Correct |
37 ms |
8312 KB |
Output is correct |
36 |
Correct |
45 ms |
8312 KB |
Output is correct |
37 |
Correct |
36 ms |
8312 KB |
Output is correct |
38 |
Correct |
35 ms |
8312 KB |
Output is correct |
39 |
Correct |
94 ms |
2000 KB |
Output is correct |
40 |
Correct |
106 ms |
2040 KB |
Output is correct |
41 |
Correct |
82 ms |
2084 KB |
Output is correct |
42 |
Correct |
84 ms |
1912 KB |
Output is correct |
43 |
Correct |
92 ms |
2012 KB |
Output is correct |
44 |
Correct |
123 ms |
2040 KB |
Output is correct |
45 |
Correct |
125 ms |
2040 KB |
Output is correct |
46 |
Correct |
127 ms |
2028 KB |
Output is correct |
47 |
Correct |
127 ms |
2004 KB |
Output is correct |
48 |
Correct |
129 ms |
1912 KB |
Output is correct |
49 |
Correct |
93 ms |
2036 KB |
Output is correct |
50 |
Correct |
76 ms |
1996 KB |
Output is correct |
51 |
Correct |
85 ms |
2040 KB |
Output is correct |
52 |
Correct |
82 ms |
1912 KB |
Output is correct |
53 |
Correct |
86 ms |
1912 KB |
Output is correct |
54 |
Correct |
41 ms |
1276 KB |
Output is correct |
55 |
Correct |
35 ms |
1272 KB |
Output is correct |
56 |
Correct |
38 ms |
1400 KB |
Output is correct |
57 |
Correct |
35 ms |
1312 KB |
Output is correct |
58 |
Correct |
42 ms |
1272 KB |
Output is correct |
59 |
Execution timed out |
2065 ms |
8440 KB |
Time limit exceeded |
60 |
Halted |
0 ms |
0 KB |
- |