There are two functions that you will need to write for this lab. The first function will swap the value of a string (char *) pointer. This swap function will accept two void pointers and swap the values. The Second, will be a recursive function that reverses the order of the strings in the list/array. When you find a solution, you will realize how simple the code in a recursive function can be. We will also use a function pointer for the swap function in the reverse function. This way the code will be more flexible making the program reusable/dynamic.

here's the code I've written so far for recursion.c:

void swapString(void **a, void **b){

void* temp;

temp = *a;

*a = *b;

*b = temp;

}

void recursiveReverse(void **listPtr, int lowIndex, int highIndex, void (*swapFunction) (void **, void **)){

if(lowIndex

swapFunction((&(*listPtr)-lowIndex),(&(*listPtr)-highIndex));

recursiveReverse(listPtr,++lowIndex,--highIndex,swapFunction);

}

else {

return;

}

}

heres the main file im using for the recursion.c file:

int main(int argc, char *argv[]) {

void* a;

void* b;

void* c;

void* d;

char* str1 = malloc(sizeof(char)*10);

str1 = "4";

char* str2 = malloc(sizeof(char)*10);

str2 = "3";

char* str3 = malloc(sizeof(char)*10);

str3 = "2";

char* str4 = malloc(sizeof(char)*10);

str4 = "1";

a = *(char**)&str1;

b = *(char**)&str2;

c = *(char**)&str3;

d = *(char**)&str4;

recursiveReverse(&a, 0, 3, swapString);

printf("Final %s ", *(char**)&str1);

printf("Final %s ", *(char**)&str2);

printf("Final %s ", *(char**)&str3);

printf("Final %s ", *(char**)&str4);

return 0;

}

heres the .h file for it :

*****

* Standard Libraries

*****/

#include

#include

#include

/*****

* Function Prototypes for recursiveReverse.c

*****/

/* Swap the value of two strings */

void swapString(void **a, void **b);

/* This is the recursiveReverse function that will reverse the order of a list */

void recursiveReverse(void **listPtr, int lowIndex, int highIndex, void (*swapFunction) (void **, void **));