>for(int index=0;index<strlen(input);index++)
Yikes! That array is 'strlened' every pass. Better would be
int i = strlen(input);
for(int index = 0; index < i; index++)
>for(int index=0;index<strlen(input);index++)
Yikes! That array is 'strlened' every pass. Better would be
int i = strlen(input);
for(int index = 0; index < i; index++)