dynamically allocated memory for a node is changed without any dereferencing?

Question

I am in week 5(data structures) and I tried to make a simple binary search tree. then I tried to create a function for getting around on this tree! this is a part of get_around function :

    printf("tree->number = %i\ntree->right = %p\ntree->left = %p\n" , tree->number ,tree- 
    >right,tree->left) ;
    printf("In which way do yo want to continue(right = r , left = l ,end = any character) ?\n") ;

    printf("&tree->right1= %p\n",&tree->right) ;
    char way ;
    scanf("%s" , &way) ;
    printf("&tree->right2=%p\n",&tree->right) ;

    if(way == 'r' && tree->right != NULL)
    {
        get_around(tree->right) ;
    } 

there are two "printf" before and after "scanf" and they should print the same thing , but they print different addresses ! when I omit scanf , address doesn't change at all and function works !!! Why my allocated memory (tree->right) should change after "scanf" ?

Answer 1

You are printing tree->right the first time and &tree->right) the second time. So those won't be the same, since the first is the address stored in your variable tree->right and the second is the address of your variable tree->right

char way ;
scanf("%s" , &way) ;

You are scanning for a string (%s) but only have space in memory for a char. The memory after the 1 char will be overwritten with the rest of the string (whatever was entered at the terminal, including a null char to end the string). That may be overwriting the tree->right variable?