How to generate an array of 256 distinct numbers

Question

I have this:

#include     
using namespace std;   
int main()
{
    int a[256];
    int b;
    int k;
    for (int i = 0; i < 256; i ++){
             


        

Answer 1

As others mentioned, use std::random_shuffle:

std::vector my_vec(256); //Reserve space for 256 numbers in advance.

for(int n = 0; n < 256; ++n)
{
  my_vec.push_back(n);
}

std::random_shuffle(my_vec.begin(), my_vec.end());