func_code_string: #include <bits/stdc++.h>   using namespace std;   using ll = long long;   using ld = long double;   const ld eps = 1e-8;   template <class U, class V>   ostream& operator<<(ostream& out, const pair<U, V>& p) {     return out <<  (  << p.first <<  ,   << p.second <<  ) ;   }   template <size_t i, class T>   ostream& print_tuple_utils(ostream& out, const T& tup) {     if constexpr (i == tuple_size<T>::value)       return out <<  ) ;     else       return print_tuple_utils<i + 1, T>(out << (i ?  ,   :  ( ) << get<i>(tup),                                          tup);   }   template <class... U>   ostream& operator<<(ostream& out, const tuple<U...>& tup) {     return print_tuple_utils<0, tuple<U...>>(out, tup);   }   template <class Con, class = decltype(begin(declval<Con>()))>   typename enable_if<!is_same<Con, string>::value, ostream&>::type operator<<(       ostream& out, const Con& container) {     out <<  { ;     for (auto it = container.begin(); it != container.end(); ++it)       out << (it == container.begin() ?    :  ,  ) << *it;     return out <<  } ;   }   template <int mod_>   struct modint {     static constexpr int mod = mod_;     int x;     modint(int xx = 0) : x(xx) {}     modint(ll xx) : x((int)(xx % mod)) {}     friend inline modint operator+(modint u, const modint& v) { return u += v; }     modint& operator+=(const modint& o) {       if ((x += o.x) >= mod) x -= mod;       return *this;     }     friend inline modint operator-(modint u, const modint& v) { return u -= v; }     modint& operator-=(const modint& o) {       if ((x -= o.x) < 0) x += mod;       return *this;     }     friend inline modint operator*(modint u, const modint& v) { return u *= v; }     modint& operator*=(const modint& o) { return *this = modint(1ll * x * o.x); }     modint pow(ll exp) const {       modint base = *this, ans = 1;       for (; exp > 0; exp >>= 1, base *= base)         if (exp & 1) ans *= base;       return ans;     }     friend inline modint operator/(modint u, const modint& v) { return u /= v; }     modint& operator/=(const modint& o) { return *this *= o.pow(mod - 2); }     friend bool operator==(const modint& u, const modint& v) {       return u.x == v.x;     }     friend ostream& operator<<(ostream& out, const modint& u) {       return out << u.x;     }   };   using mint = modint<(int)1e9 + 7>;   const int maxn = 696;   mint comb[maxn][maxn];   mint fac[maxn];   void precal() {     for (int i = (int)(0); i < (int)(maxn); ++i) {       comb[i][0] = 1;       for (int f = (int)(1); f < (int)(i + 1); ++f) {         comb[i][f] = comb[i - 1][f] + comb[i - 1][f - 1];       }     }     fac[0] = 1;     for (int i = (int)(1); i < (int)(maxn); ++i) fac[i] = fac[i - 1] * i;   }   int reduce_factor(int num) {     int ans = 1;     for (int i = 2; i * i <= num; ++i) {       if (num % i) continue;       int cnt = 0;       while (num % i == 0) {         num /= i;         cnt ^= 1;       }       if (cnt) ans *= i;     }     if (num > 1) ans *= num;     return ans;   }   mint brute(const vector<int>& a) {     auto is_perfect_sqr = [&](ll num) {       ll x = (ll)round(sqrt(num));       return x * x == num;     };     vector<int> pos(((int)a.size()));     for (int i = (int)(0); i < (int)(((int)a.size())); ++i) pos[i] = i;     mint ans = 0;     do {       bool ok = true;       for (int i = (int)(0); i < (int)(((int)a.size()) - 1); ++i) {         if (!is_perfect_sqr(1ll * a[pos[i]] * a[pos[i + 1]])) continue;         ok = false;         break;       }       ans += ok;     } while (next_permutation((pos).begin(), (pos).end()));     return ans;   }   mint solve(const vector<int>& a) {     map<int, int> cnt;     for (auto i : a) {       int rd = reduce_factor(i);       if (0)         cerr <<  [                   i                    =                << (i) <<  ]                <<  [                   rd                    =                << (rd) <<  ]   << endl;       cnt[rd]++;     }     vector<mint> dp = {1};     int cnt_have = 0;     for (auto [val, cur_cnt] : cnt) {       ;       if (0)         cerr <<  [                   val                    =                << (val) <<  ]                <<  [                   cur_cnt                    =                << (cur_cnt) <<  ]   << endl;       vector<mint> new_dp(((int)a.size()) + 2);       auto cur_fac = fac[cur_cnt];       for (int prev_same_pos = (int)(0); prev_same_pos < (int)(((int)dp.size()));            ++prev_same_pos) {         if (dp[prev_same_pos] == 0) continue;         int prev_res_pos = cnt_have + 1 - prev_same_pos;         for (int cnt_group = (int)(1); cnt_group < (int)(cur_cnt + 1);              ++cnt_group) {           ;           if (0)             cerr <<  [                       cnt_group                        =                    << (cnt_group) <<  ]   << endl;           int add_same_pos = cur_cnt - cnt_group;           for (int choose_same_pos = (int)(0);                choose_same_pos < (int)(prev_same_pos + 1); ++choose_same_pos) {             int choose_res_pos = cnt_group - choose_same_pos;             if (choose_res_pos < 0) break;             if (choose_res_pos > prev_res_pos) continue;             int new_same_pos = prev_same_pos + add_same_pos - choose_same_pos;             mint cur_ans = comb[prev_same_pos][choose_same_pos] *                            comb[prev_res_pos][choose_res_pos] *                            comb[cur_cnt - 1][cnt_group - 1] * dp[prev_same_pos];             if (0)               cerr <<  [                         choose_same_pos                          =                      << (choose_same_pos) <<  ]                      <<  [                         new_same_pos                          =                      << (new_same_pos) <<  ]                      <<  [                         cur_ans                          =                      << (cur_ans) <<  ]   << endl;             new_dp[new_same_pos] += cur_fac * cur_ans;           }         }       }       swap(dp, new_dp);       while (dp.size() and dp.back() == 0) dp.pop_back();       cnt_have += cur_cnt;       if (0)         cerr <<  [                   dp                    =                << (dp) <<  ]   << endl;       if (0)         cerr <<  [                   cnt_have                    =                << (cnt_have) <<  ]   << endl;     }     return dp[0];   }   mt19937 rng;   void check() {     while (true) {       int n = ((int)(rng() >> 1)) % 5 + 1;       vector<int> a(n);       for (int i = (int)(0); i < (int)(n); ++i)         a[i] = ((int)(rng() >> 1)) % 100 + 1;       ofstream inp( main.inp );       inp << n << endl;       for (int i = (int)(0); i < (int)(n); ++i) inp << a[i] <<    ;       inp << endl;       auto ans = solve(a);       auto exp = brute(a);       inp <<  [                ans                 =             << (ans) <<  ]             <<  [                exp                 =             << (exp) <<  ]   << endl;       inp.close();       if (ans == exp) {         cout <<  OK  << endl;         continue;       }       cout <<  FAILED  << endl;       exit(0);     }   }   int main() {     precal();     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int n;     cin >> n;     vector<int> a(n);     for (int i = (int)(0); i < (int)(n); ++i) cin >> a[i];     cout << solve(a) << endl;     return 0;   }   