sort.c

来自「c21Examples.rar」· C语言 代码 · 共 79 行

/* Inputs a list of strings from the keyboard, sorts them, */
/* and then displays them on the screen. */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#define MAXLINES 25

int get_lines(char *lines[]);
void sort(char *p[], int n);
void print_strings(char *p[], int n);

char *lines[MAXLINES];

int main( void )
{
   int number_of_lines;

   /* Read in the lines from the keyboard. */

   number_of_lines = get_lines(lines);

   if ( number_of_lines < 0 )
   {
       puts(" Memory allocation error");
       exit(-1);
   }

   sort(lines, number_of_lines);
   print_strings(lines, number_of_lines);
   return 0;
}

int get_lines(char *lines[])
{
   int n = 0;
   char buffer[80];  /* Temporary storage for each line. */

   puts("Enter one line at time; enter a blank when done.");

   while ((n < MAXLINES) && (gets(buffer) != 0) &&
          (buffer[0] != '\0'))
   {
       if ((lines[n] = (char *)malloc(strlen(buffer)+1)) == NULL)
           return -1;
       strcpy( lines[n++], buffer );
   }
   return n;

} /* End of get_lines() */

void sort(char *p[], int n)
{
   int a, b;
   char *x;

   for (a = 1; a < n; a++)
   {
       for (b = 0; b < n-1; b++)
       {
           if (strcmp(p[b], p[b+1]) > 0)
           {
               x = p[b];
               p[b] = p[b+1];
               p[b+1] = x;
           }
       }
   }
}

void print_strings(char *p[], int n)
{
   int count;

   for (count = 0; count < n; count++)
       printf("%s\n", p[count]);
}