If I have a C# array of objects and want to iterate over all pairwise combinations, how is this best accomplished? For:
int[] list = new int[3] {100, 200, 300}; This would look like:
100, 200 100, 300 200, 300 Obviously, I want a function that can take an array of any size, and preferably is generic so that any object type could work.
Try this:
public static IList<Tuple<T,T>> GetPairs<T>(IList<T> list) { IList<Tuple<T,T>> res = new List<Tuple<T,T>>(); for (int i = 0; i < list.Count(); i++) { for (int j = i + 1; j < list.Count(); j++) { res.Add(new Tuple<T, T>(list[i], list[j])); } } return res; } 
int[] input = new int[] {100, 200, 300}; List<int[]> result = new List<int[]>(); for(int i=0; i<input.Length-1; i++) { for(int j=i+1; j<input.Length; j++) { result.Add(new int[]{input[i], input[j]}); } } 
loop condition as i<input.Length-1
i=input.Length-1 is redundant, at that loop j=input.Length and nothing is executed more, I don't mean you code doesn't work, just redundant a little.int[] arr = { 800, 11, 50, 771, 649, 770, 240, 9 }; for (int i = 0; i < arr.Length; i++) { for (int j= i; j< arr.Length; j++) { if(i!=j) //Console.Write(arr[i] + " " + arr[j]); Console.WriteLine(arr[i] + " " + arr[j]); } } Instead of 'int' you can take Object type. Then you need to maintain further checking.
800 11 and 11 800, which is not what the OP wants.
