// drz-drzewa-rozpinajace.cpp : This file contains the 'main' function. Program execution begins and ends there. // #include <iostream> #include <vector> #include <algorithm> constexpr int MAXN = 5007; constexpr long long MD = 1e9 + 7; long long mat[MAXN][MAXN]; std::vector<long long> dv[MAXN]; int n; long long ppow(long long a, long long e) { long long b = 1; while (e > 0) { if (e % 2 == 1) { b *= a; b %= MD; } e /= 2; a *= a; a %= MD; } return b; } long long prev(long long a) { return ppow(a, MD - 2); } long long det() { long long res = 1; long long rv; int k; for (int i = 0; i < n; i++) { k = i; for (int j = i + 1; j < n; j++) { if (mat[j][i] != 0) { k = j; } } if (mat[k][i] == 0) { return 0; } std::swap(mat[i], mat[k]); if (i != k) { res = MD - res; } res = ((res * mat[i][i]) % MD + MD) % MD; rv = prev(mat[i][i]); for (int j = i + 1; j < n; j++) { mat[i][j] *= rv; mat[i][j] %= MD; } for (int j = 0; j < n; j++) { if (i != j && mat[j][i] != 0) { for (int k = i + 1; k < n; k++) { mat[j][k] = (mat[j][k] - (mat[i][k] * mat[j][i]) % MD + MD) % MD; } } } } return res; } int main() { std::ios_base::sync_with_stdio(0); std::cin.tie(0); std::cout.tie(0); long long l; std::cin >> n; for (int i = 0; i < n; i++) { std::cin >> l; for (long long j = 2; l > 1; j++) { while (l % j == 0) { l /= j; dv[i].push_back(j); } } } std::vector<long long> v_intersection; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (i == j) { continue; } v_intersection.clear(); std::set_intersection(dv[i].begin(), dv[i].end(), dv[j].begin(), dv[j].end(), std::back_inserter(v_intersection)); mat[i][j] = -1; for (auto u : v_intersection) { mat[i][j] *= u; } mat[i][i] -= mat[i][j]; } } n--; /* for (int i = 0; i < n; i++) { std::cout << "{"; for (int j = 0; j < n; j++) { std::cout << mat[i][j] << ','; } std::cout << "}, "; } */ std::cout << det() % MD << '\n'; } // Run program: Ctrl + F5 or Debug > Start Without Debugging menu // Debug program: F5 or Debug > Start Debugging menu // Tips for Getting Started: // 1. Use the Solution Explorer window to add/manage files // 2. Use the Team Explorer window to connect to source control // 3. Use the Output window to see build output and other messages // 4. Use the Error List window to view errors // 5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project // 6. In the future, to open this project again, go to File > Open > Project and select the .sln file
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 | // drz-drzewa-rozpinajace.cpp : This file contains the 'main' function. Program execution begins and ends there. // #include <iostream> #include <vector> #include <algorithm> constexpr int MAXN = 5007; constexpr long long MD = 1e9 + 7; long long mat[MAXN][MAXN]; std::vector<long long> dv[MAXN]; int n; long long ppow(long long a, long long e) { long long b = 1; while (e > 0) { if (e % 2 == 1) { b *= a; b %= MD; } e /= 2; a *= a; a %= MD; } return b; } long long prev(long long a) { return ppow(a, MD - 2); } long long det() { long long res = 1; long long rv; int k; for (int i = 0; i < n; i++) { k = i; for (int j = i + 1; j < n; j++) { if (mat[j][i] != 0) { k = j; } } if (mat[k][i] == 0) { return 0; } std::swap(mat[i], mat[k]); if (i != k) { res = MD - res; } res = ((res * mat[i][i]) % MD + MD) % MD; rv = prev(mat[i][i]); for (int j = i + 1; j < n; j++) { mat[i][j] *= rv; mat[i][j] %= MD; } for (int j = 0; j < n; j++) { if (i != j && mat[j][i] != 0) { for (int k = i + 1; k < n; k++) { mat[j][k] = (mat[j][k] - (mat[i][k] * mat[j][i]) % MD + MD) % MD; } } } } return res; } int main() { std::ios_base::sync_with_stdio(0); std::cin.tie(0); std::cout.tie(0); long long l; std::cin >> n; for (int i = 0; i < n; i++) { std::cin >> l; for (long long j = 2; l > 1; j++) { while (l % j == 0) { l /= j; dv[i].push_back(j); } } } std::vector<long long> v_intersection; for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { if (i == j) { continue; } v_intersection.clear(); std::set_intersection(dv[i].begin(), dv[i].end(), dv[j].begin(), dv[j].end(), std::back_inserter(v_intersection)); mat[i][j] = -1; for (auto u : v_intersection) { mat[i][j] *= u; } mat[i][i] -= mat[i][j]; } } n--; /* for (int i = 0; i < n; i++) { std::cout << "{"; for (int j = 0; j < n; j++) { std::cout << mat[i][j] << ','; } std::cout << "}, "; } */ std::cout << det() % MD << '\n'; } // Run program: Ctrl + F5 or Debug > Start Without Debugging menu // Debug program: F5 or Debug > Start Debugging menu // Tips for Getting Started: // 1. Use the Solution Explorer window to add/manage files // 2. Use the Team Explorer window to connect to source control // 3. Use the Output window to see build output and other messages // 4. Use the Error List window to view errors // 5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project // 6. In the future, to open this project again, go to File > Open > Project and select the .sln file |