RUN FAILED exit value 5 trying to swap arrays - c

Question

/*Jeremy Johnson 11-18-48
*
*The purpose of this program to to swap halves of an array. So {1 2 3 4 5 6}
*becomes {4 5 6 1 2 3} using pointer notation.
*/
#include <stdio.h>
#include <string.h>
int array[] = {1, 2, 3, 4, 5, 6}; //initialize array
void mirror(int* array, int from_index, int to_index); //prototype statment
int main() {
//define and assign pointer to array address
int *arrptr, i;
arrptr = &array[0];
//print original array
printf("Original Array: \n");
for (i = 0; i <= 5; i++) {
printf("%d", array[i]);
}
printf("\n");
//call function to swap values and mirror the array
mirror(arrptr, 0, 2);
mirror(arrptr, 3, 5);
mirror(arrptr, 0, 5);
mirror(arrptr, 1, 4);
mirror(arrptr, 2, 3);
//print final array
printf("Mirror Array: \n");
for (i = 0; i <= 5; i++) {
printf("%d", array[i]);
}
printf("\n");
return 0;
}
void mirror(int* array, int from_index, int to_index) {
//create pointer for temporary memory storage
int *temp, c[1];
temp = &c[0];
//Place to_index in temporary memory
*(temp) = *(array + to_index-1);
//Copy from_index to to_index
*(array + to_index-1) = *(array + from_index-1);
//Copy temporary value back into from_index
*(array + from_index-1) = *(temp);
return;
}
/* This code works for the function however I am not allowed to use array
notation.
c[1]=array[to_index];
array[to_index]=array[from_index];
array[from_index]=c[1]; */
I am trying to swap each half of the array; I have done so by switching the indices of the arrays by calling the mirror function 5 times and swapping the appropriate values. I was able to do so using the commented code at the bottom in place of the current function code, but now I receive and exit value 5, and I'm not sure why. (I receive no other errors within the code)

Answer 1

// perhaps swap the array by:
void mirror( int*, int* );
int main()
{
...
int *pSecondHalf = array[(sizeof(array)/sizeof(int))>>1];
// note: above line will not work for odd size array so:
if( array[(sizeof(array)/sizeof(int)] & 0x01 )
{
pSecondHalf++; // middle term in odd size array will not move
}
int *pFirstHalf = array;
const int *pLastHalf = array+((sizeof(array)/sizeof(int))>>1);
// note: following 'for' loop will execute one extra time
// for odd size array, but nothing will be changed
for( ; pFirstHalf < pLastHalf; pFirstHalf++, pSecondHalf++ )
{
mirror( pFirstHalf, pSecondHalf );
}
...
return(0);
}
// and in mirror()
void mirror( int *pVal1, int* pVal2)
{
int temp = *pVal1;
*pVal1 = *pVal2;
*pVal2 = temp;
}

Answer 2

The problem was in the mirror function. I did not move each element of the array to the temporary array using a for loop (aka counting loop). I added two loops to the function and it runs fine now.
/*Jeremy Johnson 11-18-48
*
*The purpose of this program to to swap halves of an array. So {1 2 3 4 5 6}
*becomes {4 5 6 1 2 3} using pointer notation.
*/
#include <stdio.h>
#include <string.h>
int array[] = {1, 2, 3, 4, 5, 6}; //initialize array
void mirror(int* array, int from_index, int to_index); //prototype statement
int main() {
//define and assign pointer to array address
int *arrptr, i;
arrptr = &array[0];
//print original array
printf("Original Array: \n");
for (i = 0; i <= 5; i++) {
printf("%d", array[i]);
}
printf("\n");
//call function to swap values and mirror the array
mirror(arrptr, 0, 2);
mirror(arrptr, 3, 5);
mirror(arrptr, 0, 5);
//print final array
printf("Mirror Array: \n");
for (i = 0; i <= 5; i++) {
printf("%d", array[i]);
}
printf("\n");
return 0;
}
void mirror(int* array, int from_index, int to_index) {
//create pointer for temporary memory storage
int *temp, c[6], j;
temp = &c[0];
//Place array elements in temporary memory
for (j = 0; j < 6; j++) {
*(temp + j) = *(array + j);
}
//Place mirrored halves in array respectively
for (j = 0; j <= (to_index - from_index); j++) {
*(array + from_index + j) = *(temp + to_index - j);
}
return;
}