#include <bits/stdc++.h>
using namespace std;
typedef pair<int,int> PII;
typedef pair<int,long long> PIL;
const int mod = 1e9+7;
int nwd(int a, int b){
if(b == 0) return a;
return nwd(b, a%b);
}
long long pot(long long a, int x){
if(x == 0) return 1;
if(x&1) return pot(a, x-1)*a%mod;
long long tmp = pot(a, x/2);
return tmp*tmp%mod;
}
#define mp make_pair
#define pb push_back
#define x first
#define y second
#define rep(i,b,e) for(int i=(b); i<(e); i++)
#define each(a,x) for(auto& a : (x))
#define all(x) (x).begin(),(x).end()
#define sz(x) int((x).size())
using Row = vector<long long>;
using Matrix = vector<Row>;
// copied for jagiellonian algolib
int echelon(Matrix& A, int& sign) { // O(nˆ3)
int rank = 0;
sign = 1;
rep(c, 0, sz(A[0])) {
if (rank >= sz(A)) break;
rep(i, rank+1, sz(A)) if (A[i][c]) {
swap(A[i], A[rank]);
sign *= -1;
break;
} // f98a
if (A[rank][c]) {
rep(i, rank+1, sz(A)) {
long long mult = (A[i][c] * pot(A[rank][c], mod-2))%mod;
rep(j, 0, sz(A[0]))
A[i][j] = (A[i][j]-A[rank][j]*mult)%mod;
} // f519
rank++;
} // 4cd8
//cout<<"c "<<c<<endl;
} // 36e9
return rank;
}
long long det(Matrix A) {
int s; echelon(A, s);
long long ret = s;
rep(i, 0, sz(A)) ret = (ret*A[i][i])%mod;
if(ret < 0) ret += mod;
return ret;
} // b252
int arr[5005];
int main(){
ios_base::sync_with_stdio(0);
int n;
cin>>n;
Matrix A(n);
for(int i=0;i<n;i++) cin>>arr[i];
for(int i=0;i<n;i++) for(int j=0;j<n;j++){
A[i].push_back(nwd(arr[i], arr[j]));
}
if(n == 1){
cout<<1<<endl;
return 0;
}
for(int i=0;i<n;i++){
int sum = 0;
for(int j=0;j<n;j++){
sum += A[i][j];
A[i][j] = -A[i][j];
}
A[i][i] += sum;
}
for(int i=0;i<n;i++) A[i].pop_back();
A.pop_back();
cout<<det(A)<<endl;
}
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 | #include <bits/stdc++.h> using namespace std; typedef pair<int,int> PII; typedef pair<int,long long> PIL; const int mod = 1e9+7; int nwd(int a, int b){ if(b == 0) return a; return nwd(b, a%b); } long long pot(long long a, int x){ if(x == 0) return 1; if(x&1) return pot(a, x-1)*a%mod; long long tmp = pot(a, x/2); return tmp*tmp%mod; } #define mp make_pair #define pb push_back #define x first #define y second #define rep(i,b,e) for(int i=(b); i<(e); i++) #define each(a,x) for(auto& a : (x)) #define all(x) (x).begin(),(x).end() #define sz(x) int((x).size()) using Row = vector<long long>; using Matrix = vector<Row>; // copied for jagiellonian algolib int echelon(Matrix& A, int& sign) { // O(nˆ3) int rank = 0; sign = 1; rep(c, 0, sz(A[0])) { if (rank >= sz(A)) break; rep(i, rank+1, sz(A)) if (A[i][c]) { swap(A[i], A[rank]); sign *= -1; break; } // f98a if (A[rank][c]) { rep(i, rank+1, sz(A)) { long long mult = (A[i][c] * pot(A[rank][c], mod-2))%mod; rep(j, 0, sz(A[0])) A[i][j] = (A[i][j]-A[rank][j]*mult)%mod; } // f519 rank++; } // 4cd8 //cout<<"c "<<c<<endl; } // 36e9 return rank; } long long det(Matrix A) { int s; echelon(A, s); long long ret = s; rep(i, 0, sz(A)) ret = (ret*A[i][i])%mod; if(ret < 0) ret += mod; return ret; } // b252 int arr[5005]; int main(){ ios_base::sync_with_stdio(0); int n; cin>>n; Matrix A(n); for(int i=0;i<n;i++) cin>>arr[i]; for(int i=0;i<n;i++) for(int j=0;j<n;j++){ A[i].push_back(nwd(arr[i], arr[j])); } if(n == 1){ cout<<1<<endl; return 0; } for(int i=0;i<n;i++){ int sum = 0; for(int j=0;j<n;j++){ sum += A[i][j]; A[i][j] = -A[i][j]; } A[i][i] += sum; } for(int i=0;i<n;i++) A[i].pop_back(); A.pop_back(); cout<<det(A)<<endl; } |
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