string functions in C (2)

string length 'strlen'
Mine:

int k=0;
while(*str++)
k++;
return k;

VC:

const char *eos = str;
while( *eos++ ) ;
return( (int)(eos - str - 1) );

copy n:
Mine:

for (int i=0; i< strlen....
dest[i] = source[i];
return dest;

VC:

char * mystrncpy (
char * dest,
const char * source,
int count)
char *start = dest;
while (count && (*dest++ = *source++)) /* copy string */
count--;
if (count) /* pad out with zeroes */
while (--count)
*dest++ = '\0';
return(start);