Submission #1133127

---

Source Code Expand

#include <algorithm>
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <deque>
#include <iomanip>
#include <iostream>
#include <limits>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <vector>

#define FOR(i,k,n) for (int (i)=(k); (i)<(n); ++(i))
#define rep(i,n) FOR(i,0,n)
#define pb push_back
#define all(v) begin(v), end(v)
#define debug(x) cerr<< #x <<": "<<x<<endl
#define debug2(x,y) cerr<< #x <<": "<< x <<", "<< #y <<": "<< y <<endl

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<vector<int> > vvi;
typedef vector<ll> vll;
typedef vector<vector<ll> > vvll;
template<class T> using vv=vector<vector< T > >;

int mod = 1e9 + 7;
int n;
vi x, a;

int main() {
  scanf("%d", &n);
  x.resize(n);
  a.resize(n);
  rep (i, n) {
    scanf("%d", &x[i]);
    a[i] = i;
  }
  x[0] = 1;
  FOR (i, 1, n) {
    if (x[i-1] % 2 == 0) {
      x[i] = min(x[i], x[i-1] + 1);
    } else {
      x[i] = min(x[i], x[i-1] + 2);
    }
  }
  ll ans = 1;
  int cnt = 0;
  rep (i, n) {
    if (x[i] % 2 == 0) {
      ans = ans * (i + 1 - cnt) % mod;
      cnt += 1;
    }
  }

  FOR (i, 1, n - cnt + 1) {
    ans = ans * i % mod;
  }
  printf("%lld\n", ans);

  return 0;
}

Submission Info

Judge Result