Char array comparison - c

Question

I am trying to compare two arrays. Both of these arrays contain 15 characters. I want to see if they have the same element or not.
characters being read in to the array
Array1: ATGGAATTCTCGCTC
Array2: TTGGAATTCTAGCTC
These are both in the form of arrays and are being passed in as arrayt and arraymt. n_size and m_size are the size of each array.(this is because the arrays can be any length 1-15)
int mutations(char arrayt[],char arraymt[],int n_size,int m_size)
{
int i=0,mutation=0;
do{
for(i=0;i<n_size;i++)
{
if (arrayt[i]==arraymt[i])
{
mutation=1;
}
}
}while(n_size == m_size);
return mutation;
}
This is the code I have so far for finding the differences in the two arrays. Problem is I don't know of a way that I can return if there is a difference for each of the elements. 1 is for a change and 0 is no change.
If anything is unclear let me know and I will try and clarify.

Answer 1

The code you required may be:
int* mutations(char arrayt[],char arraymt[],int n_size,int m_size)
{
int i, size;
int* mutation;
// size = min(m_size,n_size)
if n_size>m_size
size=m_size;
else
size=n_size;
endif
mutation=*malloc( sizeof(int) * size); // allocate memory for return value
for(i=0;i<size;i++)
{
if (arrayt[i]==arraymt[i])
{
mutation[i]=1;
} else {
mutation[i]=0;
}
}
return mutation;
}

Answer 2

Let's use 15 bits of an unsigned to record the results.
unsigned mutations(char arrayt[], char arraymt[], int n_size, int m_size) {
int sizemin = min(n_size, m_size);
int sizemax = max(n_size, m_size);
unsigned dest = 0;
int i;
for (i = 0; i < sizemin; i++) {
if (arrayt[i] == arraymt[i])
dest |= 1 << i;
}
for (; i < sizemax; i++) {
dest |= 1 << i; // compares against empty values are set to 1
}
return dest;
}
void foo(void) {
const char *Array1 = "ATGGAATTCTCGCTC";
const char *Array2 = "TTGGAATTCTAGCTC";
unsigned result = mutations(Array1, Array2, strlen(Array1), strlen(Array1));
// LSBit contains the result of the compare of Array1[0] vs. Array1[1]
printf("%X\n", result);
}

Answer 3

void mutations(char arrayt[],char arraymt[], int *result, int max_index)
{
int i = 0;
for (i = 0; i < max_index; i++)
{
if (arrayt[i] == arraymt[i])
{
result[i] = 0;
continue;
}
else
{
result[i] = 1;
}
}
}
int main()
{
int i = 0;
int max_index;
int *res;
char arrayt[] = "aabbccduu";
char arraymt[] = "aabcccd";
max_index = strlen(arrayt) <= strlen(arraymt) ? strlen(arrayt) : strlen(arraymt);
res = calloc (1, sizeof(int) * max_index);
if (res != NULL)
{
mutations(arrayt, arraymt, res, max_index);
while (i < max_index)
{
printf("res[i] = %d\n", res[i]);
i++;
}
free(res);
}
return 0;
}