How to generating random numbers for array enteries and XOR them in C++

My real purpose is to make an array that contain 30 elements. and each element contain 20 digit random numbers ( binary numbers). and i want to XOR each 3 elements together. for example: arr[1]^arr[2]^arr[3] arr[4]^arr[5]^arr[6] arr[7]^arr[8]^arr[9] . . arr[28]^arr[29]^arr[30]

Does anyone know how I can create this array? I would appreciate any kind of help Thanks.