A fast sort algorithm code sharing _c language

Copy Code code as follows:

/*
* QUICKSORT.C
*
* Created on:2012-4-9
* AUTHOR:LW
*/
#include <stdio.h>
#include <string.h>

typedef struct _STUDENT
{
int id;
Char name[30];
}student,*pstudent;

Student Students[20] =
{
{13, "Fox Gold"},{15, "du"},{8, "Gourd Baby"},{4, "pleasant Goat"},
{14, "Jingle Cat"},{18, "Monkey King"},{3, "Gulliver"},{6, "Coffee Cat"},
{19, "pig"},{11, "programmer"},{5, "Robinson"},{9, "Tuna"},
{10, "careless"},{12, "Week Star"},{1, "Gray wolf"},{2, "Donald Duck"},
{20, "false June"},{16, "Utopia June"},{7, "small two Lang"},{17, "Jia Baoyu"},
};

Students[] is an array that needs to be sorted, length is the number of elements of the students array
void QuickSort (student students[],int length)
{
int i,j,flag = students[0].id;
Student Stutemp;
int t;

if (length>1)
{
for (t=0;t<length;t++)
{
printf ("%d", students[t].id);
}
printf ("\ n");

Select the division point for the partition.
for (i=0,j=length-1;i<j;)
{
for (; students[i].id<flag;i++);
for (; students[j].id>flag;j--);

Stutemp.id = students[j].id;
strcpy (Stutemp.name,students[j].name);

Students[j].id = students[i].id;
strcpy (Students[j].name,students[i].name);

Students[i].id = stutemp.id;
strcpy (Students[i].name,stutemp.name);
}

Print sort Process
for (t=0;t<length;t++)
{
printf ("%d", students[t].id);
}
printf ("----sorted \ n-----------------------------------axis:%d subscript:%d\n", flag,j);

To partition and recursively call the quicksort, to operate in the original array space
QuickSort (&students[0],j+1);
QuickSort (&students[j+1],length-j-1);
}
}

int main ()
{
int i;

Print before sorting
printf ("Before: \ n");
for (i=0;i<20;i++)
{
printf ("%d%s\t", students[i].id,students[i].name);
if (!) ( (i+1)%5))
{
printf ("\ n");
}
}

QuickSort (students,20);

Print after sorting
printf ("__________________________________________________________________\n sorted: \ n");
for (i=0;i<20;i++)
{
printf ("%d%s\t", students[i].id,students[i].name);
if (!) ( (i+1)%5))
{
printf ("\ n");
}
}

return 0;
}