C语言学习：字符串的长度与比较

 

#include <io_utils.h>
#include <stdlib.h>
#include <errno.h>
#include <time.h>
#include <string.h>

void SwapString(char * *first, char * *second) {
  char * temp = *first;
  *first = *second;
  *second = temp;
}

void Shuffle(char * *array, int length) {
  srand(time(NULL));

  for (int i = length - 1; i > 0; --i) {
    int random_number = rand() % i;
    SwapString(array + i, array + random_number);
  }
}

char * *Partition(char * *low, char * *high) {
  char * pivot = *(low + (high - low) / 2);
  char * *p = low;
  char * *q = high;

  while (1) {
    while (strcmp(*p,pivot) < 0) p++;
    while (strcmp(*q, pivot) > 0) q--;

    if (p >= q) break;
    SwapString(p, q);
  }

  return q;
}

void QuickSort(char * *low, char * *high) {
  if (low >= high) return;
  char * *partition = Partition(low, high);
  QuickSort(low, partition - 1);
  QuickSort(partition + 1, high);
}

int main() {
  char *string = "Hello World!";
  PRINT_INT(strlen(string));
  //PRINT_INT(strnlen_s(string, 100)); // C11, msvc
  //PRINT_INT(strnlen(string, 100)); // gcc

  char *left = "Hello World!";
  char *right = "Hello C Programmers!";

  PRINT_INT(strcmp(left, right));
  PRINT_INT(strncmp(left, right, 5));

  // int array[];
  char *names[] = {
      "Cindy",
      "Don",
      "Andrey",
      "Elsa",
      "George",
      "Frank",
      "Benny",
  };

  QuickSort(names, names + 6);
  PRINT_ARRAY("%s, ", names, 7);
  return 0;
}