#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define F first
#define S second
using namespace std;
const ll MOD = 1000000007;
map<int, int> mp;
int dp[100005][2] = {{0}};
void valid(int x)
{
while ((x == 1 && mp[x] > 1) || (mp.find(x) != mp.end() && mp.find(x + 1) != mp.end()))
{
if (x == 1 && mp[x] > 1)
{
mp[x + 1] += mp[x] / 2;
mp[x] %= 2;
if (mp[x] == 0)
mp.erase(mp.find(x));
}
else if (mp[x] < mp[x + 1])
{
mp[x + 2] += mp[x];
mp[x + 1] -= mp[x];
mp.erase(mp.find(x));
}
else if (mp[x] == mp[x + 1])
{
mp[x + 2] += mp[x];
mp.erase(mp.find(x + 1));
mp.erase(mp.find(x));
}
else
{
mp[x + 2] += mp[x + 1];
mp[x] -= mp[x + 1];
mp.erase(mp.find(x + 1));
}
x++;
if(!(x == 1 && mp[x] > 1) && !(mp.find(x) != mp.end() && mp.find(x + 1) != mp.end()))
x++;
}
}
signed main()
{
int N;
cin >> N;
for (int i = 1; i <= N; i++)
{
int x;
cin >> x;
mp[x]++;
valid(x - 1);
valid(x);
auto iter = mp.begin();
if (iter->S >= 3)
dp[1][0] = dp[1][1] = 0;
else if (iter->S == 2)
{
if (iter->F >= 3)
dp[1][1] = (iter->F - 1) / 2;
else
dp[1][1] = 0;
dp[1][0] = 0;
}
else
{
dp[1][1] = (iter->F - 1) / 2;
dp[1][0] = 1;
}
++iter;
for (int i = 2; i <= mp.size(); i++)
{
if (iter->S >= 3)
dp[i][0] = dp[i][1] = 0;
else if (iter->S == 2 && prev(iter)->S == 2)
{
dp[i][1] = (dp[i - 1][1] * ((iter->F - prev(iter)->F - 1) / 2)) % MOD;
dp[i][0] = 0;
}
else if (iter->S == 2 && prev(iter)->S == 1)
{
dp[i][1] = (dp[i - 1][1] * ((iter->F - prev(iter)->F) / 2) +
dp[i - 1][0] * ((iter->F - prev(iter)->F - 1) / 2)) %
MOD;
dp[i][0] = 0;
}
else if (iter->S == 1 && prev(iter)->S == 2)
{
dp[i][1] = dp[i - 1][1] * ((iter->F - prev(iter)->F - 1) / 2) % MOD;
dp[i][0] = dp[i - 1][1];
}
else if (iter->S == 1 && prev(iter)->S == 1)
{
dp[i][1] = (dp[i - 1][1] * ((iter->F - prev(iter)->F) / 2) +
dp[i - 1][0] * ((iter->F - prev(iter)->F - 1) / 2)) %
MOD;
dp[i][0] = (dp[i - 1][1] + dp[i - 1][0]) % MOD;
}
++iter;
}
//for (pii i : mp)
// cout << "(" << i.F << ", " << i.S << ") ";
cout << (dp[mp.size()][0] + dp[mp.size()][1]) % MOD << '\n';
}
}
/*
1 = 1
2 = 2
3 = 1 + 2, 3
4 = 1 + 3
5 = 2 + 3, 5
6 = 5 + 1, 1 + 2 + 3
7 = 5 + 2,
8 = 5 + 3, 8, 1 + 2 + 5,
*/
Compilation message
fib.cpp: In function 'int main()':
fib.cpp:76:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::map<int, int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
76 | for (int i = 2; i <= mp.size(); i++)
| ~~^~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |