#include <chrono> #include <cassert> #include <string> #include <array> #include <deque> #include <map> #include <queue> #include <set> #include <unordered_map> #include <unordered_set> #include <vector> #include <iterator> #include <algorithm> #include <cmath> #include <complex> #include <numeric> #include <random> #include <ios> #include <iostream> #include <bitset> using namespace std; #define fwd(i, a, b) for (int i = (a); i < (b); ++ i) #define rep(i, n) for (int i = 0; i < (n); ++ i) #define all(x) (x).begin(), (x).end() #define sz(x) ((int)x.size()) #define st first #define nd second #define pii pair<int, int> #define vi vector<int> #define fastio ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0) #define ll long long #ifdef LOCAL template<typename Stream, typename T1, typename T2> Stream& operator << (Stream& out, pair<T1, T2> a) {return out << "(" << a.st << ", " << a.nd << ")";} template<typename Stream, typename T> Stream &operator << (Stream& out, T v) { out << "{"; int i = 0; for (auto x : v) out << x << ((++ i) != sz(v) ? ", " : ""); return out << "}"; } template<typename... Args> void dump(Args... x) {((cerr << x << ", "), ...) << '\n';} #define debug(x...) cerr << "[" #x "]: ", dump(x) #else #define debug(...) 0 #endif const ll mod = 1000 * 1000 * 1000 + 7; int32_t main() { fastio; int n; cin >> n; vector<vector<ll> > a(n, vector<ll>(n, 0)); vi b(n); rep(i, n) cin >> b[i]; rep(i, n) rep(j, i) { int g = gcd(b[i], b[j]); a[i][i] += g; a[j][j] += g; a[i][j] = a[j][i] = mod - g; } -- n; ll ans = 1; rep(i, n) { fwd(j, i + 1, n) { while (a[j][i] != 0) { ll t = a[i][i] / a[j][i]; if (t) fwd(k, i, n) a[i][k] = (a[i][k] - a[j][k] * t) % mod; swap(a[i], a[j]); ans *= -1; } } ans = ans * a[i][i] % mod; if (!ans) { cout << "0\n"; return 0; } } cout << (ans + mod) % mod << '\n'; return 0; }
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 | #include <chrono> #include <cassert> #include <string> #include <array> #include <deque> #include <map> #include <queue> #include <set> #include <unordered_map> #include <unordered_set> #include <vector> #include <iterator> #include <algorithm> #include <cmath> #include <complex> #include <numeric> #include <random> #include <ios> #include <iostream> #include <bitset> using namespace std; #define fwd(i, a, b) for (int i = (a); i < (b); ++ i) #define rep(i, n) for (int i = 0; i < (n); ++ i) #define all(x) (x).begin(), (x).end() #define sz(x) ((int)x.size()) #define st first #define nd second #define pii pair<int, int> #define vi vector<int> #define fastio ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0) #define ll long long #ifdef LOCAL template<typename Stream, typename T1, typename T2> Stream& operator << (Stream& out, pair<T1, T2> a) {return out << "(" << a.st << ", " << a.nd << ")";} template<typename Stream, typename T> Stream &operator << (Stream& out, T v) { out << "{"; int i = 0; for (auto x : v) out << x << ((++ i) != sz(v) ? ", " : ""); return out << "}"; } template<typename... Args> void dump(Args... x) {((cerr << x << ", "), ...) << '\n';} #define debug(x...) cerr << "[" #x "]: ", dump(x) #else #define debug(...) 0 #endif const ll mod = 1000 * 1000 * 1000 + 7; int32_t main() { fastio; int n; cin >> n; vector<vector<ll> > a(n, vector<ll>(n, 0)); vi b(n); rep(i, n) cin >> b[i]; rep(i, n) rep(j, i) { int g = gcd(b[i], b[j]); a[i][i] += g; a[j][j] += g; a[i][j] = a[j][i] = mod - g; } -- n; ll ans = 1; rep(i, n) { fwd(j, i + 1, n) { while (a[j][i] != 0) { ll t = a[i][i] / a[j][i]; if (t) fwd(k, i, n) a[i][k] = (a[i][k] - a[j][k] * t) % mod; swap(a[i], a[j]); ans *= -1; } } ans = ans * a[i][i] % mod; if (!ans) { cout << "0\n"; return 0; } } cout << (ans + mod) % mod << '\n'; return 0; } |