How do I insert random integers into a list?

Question

Help. Struggling with trying to figure this out.

Vulpes · Answer

Try this: using System; using System.Collections.Generic; class Program { static void Main() { Random r = new Random(); var list = new List (); // add n distict integers between 0 and m inclusive int n = 20; int m = 99; for(int i = 0; i { int num = r.Next(m + 1); if (!list.Contains(num)) { list.Add(num); } else { --i; } } // print them out in sorted order; list.Sort(); foreach(int i in list) Console.WriteLine(i); Console.ReadKey(); } }

Vulpes · Answer

OK but that will inevitably mean some duplication as you need to choose more numbers (30) than there are in the range (20). Anyway, the code simplifies to this: using System; using System.Collections.Generic; class Program { static void Main() { Random r = new Random(); var list = new List (); // add 30 integers between 1 and 20 inclusive for(int i = 0; i { int num = r.Next(1, 21); // 1 to 20 (excludes 21) list.Add(num); } // print them out in sorted order; list.Sort(); foreach(int i in list) Console.WriteLine(i); Console.ReadKey(); } }

Barb Walton · Answer

Appreciate the response. It doesn't work for me. I need to chose 30 random integers to a list from 1 to 20.

Munesh Sharma · Answer

http://stackoverflow.com/questions/17530306/getting-random-numbers-from-a-list-of-integers

Abhay Shanker · Answer

try with this Random rand = new Random(); List result = new List (); HashSet check = new HashSet (); for (Int32 i = 0; i int curValue = rand.Next(1, 100000); while (check.Contains(curValue)) { curValue = rand.Next(1, 100000); } result.Add(curValue); check.Add(curValue); }

How do I insert random integers into a list?

Answers (5)