/* Triangle, square, pentagonal, hexagonal, heptagonal, and octagonal numbers are all figurate (polygonal) numbers and are generated by the following formulae: Triangle P3,n=n(n+1)/2 1, 3, 6, 10, 15, ... Square P4,n=n2 1, 4, 9, 16, 25, ... Pentagonal P5,n=n(3n−1)/2 1, 5, 12, 22, 35, ... Hexagonal P6,n=n(2n−1) 1, 6, 15, 28, 45, ... Heptagonal P7,n=n(5n−3)/2 1, 7, 18, 34, 55, ... Octagonal P8,n=n(3n−2) 1, 8, 21, 40, 65, ... The ordered set of three 4-digit numbers: 8128, 2882, 8281, has three interesting properties. The set is cyclic, in that the last two digits of each number is the first two digits of the next number (including the last number with the first). Each polygonal type: triangle (P3,127=8128), square (P4,91=8281), and pentagonal (P5,44=2882), is represented by a different number in the set. This is the only set of 4-digit numbers with this property. Find the sum of the only ordered set of six cyclic 4-digit numbers for which each polygonal type: triangle, square, pentagonal, hexagonal, heptagonal, and octagonal, is represented by a different number in the set. */ #include #include #include #include #include using namespace std; uint triangle(uint n){ return n * (n + 1) / 2; } uint square(uint n){ return n * n; } uint pentagonal(uint n){ return n * (3 * n - 1) / 2; } uint hexagonal(uint n){ return n * (2 * n - 1); } uint heptagonal(uint n){ return n * (5 * n - 3) / 2; } uint octogonal(uint n){ return n * (3 * n - 2); } bool validEnd(uint n){ return n % 100 >= 10; } void fillVector(std::vector & toFill, const uint bitmask, uint (*calc)(uint n)){ uint value = calc(0); for(uint i = 0; value < 10000; ++i){ if(value >= 1000 && validEnd(value)){ toFill[value] |= bitmask; } value = calc(i + 1); } } // Non-recursive version of Heap's algorithm for permutations // Source: https://en.wikipedia.org/wiki/Heap%27s_algorithm vector> permutations(uint n, vector & A){ vector> result; vector c(n, 0); result.push_back(A); uint i = 1; while(i < n){ if(c[i] < i){ if(i % 2 == 0){ swap(A[0], A[i]); } else{ swap(A[c[i]], A[i]); } result.push_back(A); c[i] += 1; i = 1; } else{ c[i] = 0; i++; } } return result; } bool checkCyclicness(const vector & v){ for(int i = 0; i < 5; ++i){ uint end = v[i] % 100; uint start = v[i + 1] / 100; if(end != start){ return false; } } if(v[5] % 100 != v[0] / 100){ return false; } return true; } void search(vector & sequence, uint mask = 0){ } int main(){ cout << "Hello this is Patrick" << endl; auto start = chrono::high_resolution_clock::now(); // creating big vector with the numeric values and their corresponding mask uint finalMask = 0b111111000; // Finally learned what exactly it means when 1 << n, which is nice vector all(10000, 0); fillVector(all, 1 << 3, triangle); fillVector(all, 1 << 4, square); fillVector(all, 1 << 5, pentagonal); fillVector(all, 1 << 6, hexagonal); fillVector(all, 1 << 7, heptagonal); fillVector(all, 1 << 8, octogonal); cout << "Cycle not found" << endl; auto duration = chrono::duration_cast(chrono::high_resolution_clock::now() - start); cout << (float)duration.count()/1000 << endl; return 0; }