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#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
#define print_int_expr_and_value(n)            printf("%6s == %d\n", (#n), (n))
#define print_address_expr_and_value(address)  printf("%6s == %p\n", (#address), (void*)(address))
// swap_wrong_2(…) - CORRECT

void swap_wrong_2(int** a_a_lhs, int** a_a_rhs) {
    int* a_lhs = *a_a_lhs;   // a_a_lhs is an int**  so  *a_a_lhs will be an int*
    int* a_rhs = *a_a_rhs;   // 
    *a_a_lhs = a_rhs;
    *a_a_rhs = a_lhs;
}

int main(int argc, char* argv[]) {
    int n1 =   3;
    int n2 = 100;
    printf("BEFORE:\n");
    print_int_expr_and_value(n1);
    print_int_expr_and_value(n2);

    int* a_n1 = &n1;
    int* a_n2 = &n2;
    print_address_expr_and_value(&n1);
    print_address_expr_and_value(&n2);
    print_address_expr_and_value(a_n1);
    print_address_expr_and_value(a_n2);

    swap_wrong_2(&a_n1, &a_n2);
    printf("\nCalled swap(&a_n1, &a_n2)\n\n");

    printf("AFTER:\n");
    print_int_expr_and_value(n1);
    print_int_expr_and_value(n2);
    printf("Q1:  No  ... neither n1 nor n2 changed\n");
    print_address_expr_and_value(&n1);
    print_address_expr_and_value(&n2);
    printf("Q2:  No ... neither &n1 nor &n2 changed\n");
    print_address_expr_and_value(a_n1);
    print_address_expr_and_value(a_n2);
    printf("Q3:  Yes ... a_n1 and a_n2 were swapped\n");
    print_int_expr_and_value(*a_n1);
    print_int_expr_and_value(*a_n2);

    // Q1:  Will    n1 and/or    n2 change?      A:  No
    // Q2:  Will   &n1 and/or   &n2 change?
    // Q3:  Will  a_n1 and/or  a_n2 change?
    // Q4:  Will *a_n1 and/or *a_n2 change?
    return EXIT_SUCCESS;
}
/* vim: set tabstop=4 shiftwidth=4 fileencoding=utf-8 noexpandtab: */

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