#include "str.h" #include size_t strlen(const char *str) { size_t size = 0; for (; (str[size]) != '\0'; size++) { } return size; } char *str_reverse(char *str) { char *str_ptr = str; size_t size = strlen(str); char return_str[size]; for (size_t i = 0; i < size; i++) return_str[size - i - 1] = str[i]; for (size_t i = 0; i < size; i++) *str_ptr++ = return_str[i]; return str; } char *itoa(int num, char *str, int base) { char *str_ptr = str; for (; num;) { *str_ptr++ = num % base + 48; num /= base; } str_reverse(str); return str; }