1 files changed, 107 insertions, 0 deletions
diff --git a/reference/C/EXAMPLES/qsort2.c b/reference/C/EXAMPLES/qsort2.c
new file mode 100644
index 0000000..d169261
--- /dev/null
+++ b/reference/C/EXAMPLES/qsort2.c
@@ -0,0 +1,107 @@
+/************************************************************************
+ *
+ * Purpose: To read numbers entered by the user and sort them.
+ * Author:  M.J.Leslie
+ * Date:    30-Nov-94
+ *
+ ************************************************************************/
+
+/********** Preprocessor  ***********************************************/
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+/********** Functions ***************************************************/
+
+int read_nums(int *);
+void display_nums(int *);
+int comp_nums(const int *, const int *);
+
+/********** main ********************************************************/
+
+main()
+{
+  int numbers[30];			/* Numbers to be sorted.	*/
+  int how_many=0;			/* Number of numbers entered	*/
+
+					/* Get the numbers		*/
+  how_many = read_nums(numbers);
+
+  puts("\nThese are the unsorted numbers\n");
+  display_nums(numbers);
+
+					/* SORT the numbers held in 
+					 * 'numbers'.			*/
+  qsort(
+	numbers, 			/* Pointer to elements		*/
+	how_many, 			/* Number of elements		*/
+	sizeof(int),  			/* size of one element.		*/
+	(void *)comp_nums		/* Pointer to comparison function */
+	);
+
+  puts("\nThese are the sorted numbers\n");
+  display_nums(numbers);
+}
+
+/************************************************************************
+ *
+ * comp_nums: Compare two numbers.
+ *
+ ************************************************************************/
+
+int comp_nums(const int *num1, const int *num2)
+{
+  if (*num1 <  *num2) return -1;
+  if (*num1 == *num2) return  0;
+  if (*num1 >  *num2) return  1;
+}
+
+/************************************************************************
+ *
+ * readnums: read numbers from the keyboard and put them into an array.
+ *
+ ************************************************************************/
+
+int read_nums(int *array)
+{
+
+  char data[80];			/* Data entered by the user	*/
+  int inc=0;
+
+  puts("\n\tPlease enter some integer numbers");
+  puts("\tno checking is made on the data you enter....");
+  printf("\t==> ");
+
+  gets(data);
+					/* Assume we have valid data.	
+					 * Put it into an array.	*/
+  *(array+inc) = atoi(strtok(data," "));
+  inc++;
+   
+  while ( *(array+inc) = atoi(strtok(NULL," "))) inc++;
+
+					/* Return the number of items
+					 * stored in 'array'.		*/
+  return inc++;
+}
+
+/************************************************************************
+ *
+ * display_nums: Display the numbers
+ *
+ ************************************************************************/
+
+void display_nums(int *array)
+{
+					/* NULL is a pointer to 0, 
+					 * so it must be cast to an
+					 * integer			*/
+  while ( *array != (int)NULL)
+  {
+    printf("%d ",*array);
+    array++;
+  }
+
+  puts("");
+}