#include <iostream> #include <set> #include <array> #include <algorithm> #include <bitset> #include <vector> #include <map> // https://en.wikipedia.org/wiki/Pythagorean_quadruple #define TYPE std::array<unsigned, 4> #define SHIFT 25 std::map<int, std::set<int>> factors; std::set<int> get_factors(int val) { std::set<int> res; // if (factors.count(val)) // { // res = factors[val]; // } // else // { for (int f = 1; f * f <= val; f++) { if (val % f == 0) { res.insert(f); if (f * f != val && f != 1) { res.insert(val / f); } } } // } return res; } void init_factors() { for (int i = 1; i < 1000; i++) { factors[i] = get_factors(i); } } void print(std::set<TYPE> data) { for (TYPE d : data) { for (auto x : d) { std::cout << x << ' '; } std::cout << '\n'; } std::cout << "---\n"; } int main() { std::set<TYPE> data; int n; int c, d, l, m; TYPE quad; std::set<int> tester; unsigned long long res = 0ULL; // init_factors(); std::cin >> n; for (int a = 2; a < n; a += 2) { // different parity for (int b = 1; a * a + b * b + 1 < n * n; b += 2) { for (int p : get_factors(a * a + b * b)) { c = (a * a + b * b - p * p) / 2 / p; d = (a * a + b * b + p * p) / 2 / p; if (c > 0 && d <= n) { quad[0] = a; quad[1] = b; quad[2] = c; quad[3] = d; std::sort(quad.begin(), quad.end()); // std::cout << a << ' ' << b << ' ' << c << ' ' << d << ' ' << pp << '\n'; data.insert(quad); } } } // both even for (int b = a; a * a + b * b < n * n; b += 2) { l = a >> 1; m = b >> 1; for (int p : get_factors(l * l + m * m)) { c = (l * l + m * m - p * p) / p; d = (l * l + m * m + p * p) / p; if (c > 0 && d <= n) { quad[0] = a; quad[1] = b; quad[2] = c; quad[3] = d; std::sort(quad.begin(), quad.end()); data.insert(quad); } } } } // print(data); for (TYPE d : data) { tester.clear(); for (auto x : d) { tester.insert(x); } res += tester.size() - 1; } std::cout << res << '\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 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 | #include <iostream> #include <set> #include <array> #include <algorithm> #include <bitset> #include <vector> #include <map> // https://en.wikipedia.org/wiki/Pythagorean_quadruple #define TYPE std::array<unsigned, 4> #define SHIFT 25 std::map<int, std::set<int>> factors; std::set<int> get_factors(int val) { std::set<int> res; // if (factors.count(val)) // { // res = factors[val]; // } // else // { for (int f = 1; f * f <= val; f++) { if (val % f == 0) { res.insert(f); if (f * f != val && f != 1) { res.insert(val / f); } } } // } return res; } void init_factors() { for (int i = 1; i < 1000; i++) { factors[i] = get_factors(i); } } void print(std::set<TYPE> data) { for (TYPE d : data) { for (auto x : d) { std::cout << x << ' '; } std::cout << '\n'; } std::cout << "---\n"; } int main() { std::set<TYPE> data; int n; int c, d, l, m; TYPE quad; std::set<int> tester; unsigned long long res = 0ULL; // init_factors(); std::cin >> n; for (int a = 2; a < n; a += 2) { // different parity for (int b = 1; a * a + b * b + 1 < n * n; b += 2) { for (int p : get_factors(a * a + b * b)) { c = (a * a + b * b - p * p) / 2 / p; d = (a * a + b * b + p * p) / 2 / p; if (c > 0 && d <= n) { quad[0] = a; quad[1] = b; quad[2] = c; quad[3] = d; std::sort(quad.begin(), quad.end()); // std::cout << a << ' ' << b << ' ' << c << ' ' << d << ' ' << pp << '\n'; data.insert(quad); } } } // both even for (int b = a; a * a + b * b < n * n; b += 2) { l = a >> 1; m = b >> 1; for (int p : get_factors(l * l + m * m)) { c = (l * l + m * m - p * p) / p; d = (l * l + m * m + p * p) / p; if (c > 0 && d <= n) { quad[0] = a; quad[1] = b; quad[2] = c; quad[3] = d; std::sort(quad.begin(), quad.end()); data.insert(quad); } } } } // print(data); for (TYPE d : data) { tester.clear(); for (auto x : d) { tester.insert(x); } res += tester.size() - 1; } std::cout << res << '\n'; return 0; } |