gh-card | : octocat : GitHub Repository Card for Any Web Site | Static Site Generator library

Your problem stems from the fact that cards is declared as a static array in the randomize_deck() function. So, the first call to randomize_deck() fills this array with random cards, returning a pointer to cards. Then the second call to randomize_deck() fills the same static array with new random cards, and returns a pointer to the same static array. After all of this, both person_a and person_b point to the same static array.

One solution is to change the randomize_deck() function to accept an array argument, with a return type of void. Also, it would be best to pass the size of the array to randomize_deck(), instead of relying on a global constant. And note that in the code below I have changed the array index variables to type size_t, which is an unsigned integer type guaranteed to hold any array index, and the correct type for array indices.