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

#include 
#include 
#include 

int main(int argc, const char * argv[])
{
    std::vector items(256);

    std::iota(items.begin(),items.end(),0);

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

    for(auto i:items)
        std::cout<