using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; /* Write a program which will take a number as input and print a spiral from 1 till the square of the number. For example: Input: 3 Output: 9 8 7 2 1 6 3 4 5 Input: 4 Output: 16 15 14 13 5 4 3 12 6 1 2 11 7 8 9 10 Bonus task: Try to print the output in an exact square form. */ namespace SoloLearn { class Program { static void Main(string[] args) { if(IsInputValid(out int inp)) { Spiral s = new Spiral(inp); Print(s); } } // Check given input static bool IsInputValid(out int input) { bool result = false; result = int.TryParse(Console.ReadLine(), out input); result = input > 0; return result ; } // Print the spiral to the console static void Print(Spiral s) { int i, j; string line; string[] space = { "", " ", " ", " " }; for (i = 0; i < s.Length; i++) { line = ""; for (j = 0; j < s.Length; j++) { line += string.Format($"{s[i, j]}"); line += s[i, j] < 10 ? space[3] : s[i, j] < 100 ? space[2] : space[1]; } Console.WriteLine(line); Console.WriteLine(); } Console.WriteLine(); } } class Spiral { int[][] spiral; int dim; // Initialize the first spiral, 1 dimension private Spiral() { dim = 1; spiral = new int[dim][]; spiral[0] = new int[dim]; spiral[0][0] = dim; } // Create a dimension + 1 size spiral, and inherit previous private Spiral(Spiral prev) { int i, j; dim = prev.Length + 1; spiral = new int[dim][]; for (i = 0; i < dim; i++) spiral[i] = new int[dim]; for (i = 1; i < dim; i++) { for (j = 0; j < dim - 1; j++) { spiral[i][j] = prev[i - 1, j]; } } } // Main Ctor, create the spiral public Spiral(int n) { Spiral prev = new Spiral(); // 1 dimension spiral, start dim = n; spiral = new int[dim][]; // final size of the spiral for (n = 0; n < dim; n++) spiral[n] = new int[dim]; n = 1; // while not the final dimension // build previous spirals, rotate, inherit, fill up while(++n <= dim) { Inherit(ref prev); Fill(prev); } // if targeted dimension reached, pass the temp spiral for (n = 0; n < dim; n++) spiral[n] = prev[n]; } // get the dimension of the spiral public int Length { get { return dim; } } // getter/setter of spiral public int this[int i, int j] { get { return spiral[i][j]; } set { spiral[i][j] = value; } } // helper for inheritance private int[] this[int i] { get { return spiral[i]; } } // Rotate the spiral 180 degrees void Rotate(Spiral prev) { if (prev.Length == 1) return; int i, j, temp, mi = prev.Length - 1; int[] max = new int[2]; max[0] = prev.Length % 2 == 0 ? prev.Length / 2 : prev.Length / 2 + 1; max[1] = prev.Length; for (i = 0; i < max[0]; i++) { if (i == mi - i) max[1] /= 2; for (j = 0; j < max[1]; j++) { temp = prev[mi - i, mi - j]; prev[mi - i, mi - j] = prev[i, j]; prev[i, j] = temp; } } } // Inherit the previous spiral void Inherit(ref Spiral prev) { Rotate(prev); prev = new Spiral(prev); } // Build the outer layer of the spiral void Fill(Spiral prev) { int i, j, len = prev.Length; int max = len * len; for (j = 0; j < len; j++) prev[0, j] = max--; for (i = 1; i < len; i++) prev[i, j - 1] = max--; } } }

Numbers Spiral