Scan a string argument and print the first 'n' character found

size_t strlen(const char *s)

void write_str(char *str)

char *strchr(const char *s, int c)

size_t strcspn(const char *s, const char *reject)

char *strstr(const char *haystack, const char *needle)

Display the last lowercase 'e' found in a string

char *strrchr(const char *s, int c)

char *find_any_char(const char *text, const char *needles)

size_t prefix_span(const char *text, const char *allowed)

Check if the first string is a case-insensitive ordered subsequence of the second

Check whether the first string is an ordered subsequence of the second, printing yes or no

Print the longest palindromic substring contained in a string passed on the command line