#pragma GCC optimize("O3") #include <bits/stdc++.h> // #include <ext/pb_ds/assoc_container.hpp> // using namespace __gnu_pbds; // gp_hash_table<int, int> mapka; using namespace std; #define PB push_back #define MP make_pair #define LL long long #define int LL #define FOR(i,a,b) for(int i = (a); i <= (b); i++) #define RE(i,n) FOR(i,1,n) #define REP(i,n) FOR(i,0,(int)(n)-1) #define R(i,n) REP(i,n) #define VI vector<int> #define PII pair<int,int> #define LD long double #define FI first #define SE second #define st FI #define nd SE #define ALL(x) (x).begin(), (x).end() #define SZ(x) ((int)(x).size()) template<class C> void mini(C &a4, C b4) { a4 = min(a4, b4); } template<class C> void maxi(C &a4, C b4) { a4 = max(a4, b4); } template<class TH> void _dbg(const char *sdbg, TH h){ cerr<<sdbg<<'='<<h<<endl; } template<class TH, class... TA> void _dbg(const char *sdbg, TH h, TA... a) { while(*sdbg!=',')cerr<<*sdbg++; cerr<<'='<<h<<','; _dbg(sdbg+1, a...); } template<class T> ostream &operator<<(ostream& os, vector<T> V) { os << "["; for (auto vv : V) os << vv << ","; return os << "]"; } template<class L, class R> ostream &operator<<(ostream &os, pair<L,R> P) { return os << "(" << P.st << "," << P.nd << ")"; } #ifdef LOCAL #define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__) #else #define debug(...) (__VA_ARGS__) #define cerr if(0)cout #endif const int P = 1e9 + 7; const int P2 = P * P; int pot(int a,int w){ int r = 1; while(w){ if(w & 1){ r *= a; r %= P; } w/=2; a *= a; a %= P; } return r; } inline void add(int &a,int b){ a += b; if(a >= P2) a -= P2; } int32_t main(){ ios_base::sync_with_stdio(0); cin.tie(0); cout << fixed << setprecision(11); cerr << fixed << setprecision(6); int n; cin >> n; vector<int> t(n); R(i,n){ cin >> t[i]; } vector<vector<int>> m(n,vector<int>(n)); R(i,n)R(j,i){ int pom = gcd(t[i],t[j]); m[i][i] += pom; m[j][j] += pom; m[i][j] -= pom; m[j][i] -= pom; } m.pop_back(); for(auto &el:m)el.pop_back(); debug(m); n--; R(i,n)R(j,n){ if(m[i][j] < 0)m[i][j] += P; } int znak = 0; R(j,n){ int gd = -1; for(int i=j;i < n;i++){ m[i][j] %= P; if(m[i][j]){ gd = j; break; } } if(gd == -1){ cout << "0\n"; return 0; } if(gd != j){ znak = !znak; swap(m[j],m[gd]); } R(i,n){ m[j][i] %= P; } int pom = P-pot(m[j][j], P-2); pom %= P; for(int i = j+1;i < n;i++){ m[i][j] %= P; int coef = pom * m[i][j] % P; for(int k = j; k < n; k++){ add(m[i][k], coef * m[j][k]); } } } int res = znak ? P-1 : 1; R(i,n)res = res * m[i][i] % P; cout << res << "\n"; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 | #pragma GCC optimize("O3") #include <bits/stdc++.h> // #include <ext/pb_ds/assoc_container.hpp> // using namespace __gnu_pbds; // gp_hash_table<int, int> mapka; using namespace std; #define PB push_back #define MP make_pair #define LL long long #define int LL #define FOR(i,a,b) for(int i = (a); i <= (b); i++) #define RE(i,n) FOR(i,1,n) #define REP(i,n) FOR(i,0,(int)(n)-1) #define R(i,n) REP(i,n) #define VI vector<int> #define PII pair<int,int> #define LD long double #define FI first #define SE second #define st FI #define nd SE #define ALL(x) (x).begin(), (x).end() #define SZ(x) ((int)(x).size()) template<class C> void mini(C &a4, C b4) { a4 = min(a4, b4); } template<class C> void maxi(C &a4, C b4) { a4 = max(a4, b4); } template<class TH> void _dbg(const char *sdbg, TH h){ cerr<<sdbg<<'='<<h<<endl; } template<class TH, class... TA> void _dbg(const char *sdbg, TH h, TA... a) { while(*sdbg!=',')cerr<<*sdbg++; cerr<<'='<<h<<','; _dbg(sdbg+1, a...); } template<class T> ostream &operator<<(ostream& os, vector<T> V) { os << "["; for (auto vv : V) os << vv << ","; return os << "]"; } template<class L, class R> ostream &operator<<(ostream &os, pair<L,R> P) { return os << "(" << P.st << "," << P.nd << ")"; } #ifdef LOCAL #define debug(...) _dbg(#__VA_ARGS__, __VA_ARGS__) #else #define debug(...) (__VA_ARGS__) #define cerr if(0)cout #endif const int P = 1e9 + 7; const int P2 = P * P; int pot(int a,int w){ int r = 1; while(w){ if(w & 1){ r *= a; r %= P; } w/=2; a *= a; a %= P; } return r; } inline void add(int &a,int b){ a += b; if(a >= P2) a -= P2; } int32_t main(){ ios_base::sync_with_stdio(0); cin.tie(0); cout << fixed << setprecision(11); cerr << fixed << setprecision(6); int n; cin >> n; vector<int> t(n); R(i,n){ cin >> t[i]; } vector<vector<int>> m(n,vector<int>(n)); R(i,n)R(j,i){ int pom = gcd(t[i],t[j]); m[i][i] += pom; m[j][j] += pom; m[i][j] -= pom; m[j][i] -= pom; } m.pop_back(); for(auto &el:m)el.pop_back(); debug(m); n--; R(i,n)R(j,n){ if(m[i][j] < 0)m[i][j] += P; } int znak = 0; R(j,n){ int gd = -1; for(int i=j;i < n;i++){ m[i][j] %= P; if(m[i][j]){ gd = j; break; } } if(gd == -1){ cout << "0\n"; return 0; } if(gd != j){ znak = !znak; swap(m[j],m[gd]); } R(i,n){ m[j][i] %= P; } int pom = P-pot(m[j][j], P-2); pom %= P; for(int i = j+1;i < n;i++){ m[i][j] %= P; int coef = pom * m[i][j] % P; for(int k = j; k < n; k++){ add(m[i][k], coef * m[j][k]); } } } int res = znak ? P-1 : 1; R(i,n)res = res * m[i][i] % P; cout << res << "\n"; } |