how to create a random int[] [duplicate]

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• Most efficient way to randomly “sort” (Shuffle) a list of integers in C# 12 answers

I need to create a random array of int with certain parameters.

int[] test = new int[80];
Random random = new Random();

I need to assign 1's and 0's, randomly to the array. I know how to do that.

test[position] = Random.Next(0,2);//obviously with a for loop

But I need to have exactly 20 1's, but they need to be randomly positioned in the array. I don't know how to make sure that the 1's are randomly positioned, AND that there are exactly 20 1's. The rest of the positions in the array would be assigned 0.