#include <stdio.h>
#include <string.h>
#define max 10
struct nick
{
char a[10];
};
void quicksort(struct nick items[], int left, int right); //function for quick sort
int main()
{
FILE *fp;
int i=0,k=0,n;
char fname[10],str[10],c;
struct nick name[max];
printf("Enter the filename : ");
scanf("%s",fname);
printf("\nEnter the number of products : ");
scanf("%d",&n);
printf("Enter %d product name : \n",n);
fp=fopen(fname,"w");
for(i=0;i<n;i++)
{
scanf("%s",name);
fprintf(fp,"%s ",name);
}
fclose(fp);
i=0;
fp=fopen(fname,"r"); //open file in read mode
while((c=getc(fp))!=EOF)
{
if(c==' ')
{
str[i]='\0';
strcpy(name[k].a,str); //copy string name to name
i=0;
k++;
}
else
{
str[i]=c;
i++;
}
}
fclose(fp);
printf("\nInitial contents of file\n");
for(i=0; i<k; i++)
printf("%s,", name[i].a);
quicksort(name,0,k-1); //calling quicksort
printf("\n\nAfter applying quick sort \n");
for(i=0; i<k; i++)
{
printf("%s,", name[i].a); //printing sorted
}
return 0;
}
//function for quick sort
void quicksort(struct nick items[],int first,int last)
{
int j,i,pivot;
char temp[10];
if(first<last)
{
pivot=first;
i=first;
j=last;
while(i<j)
{
while((strcmp(items[i].a,items[pivot].a))<0)
i++;
while((strcmp(items[j].a,items[pivot].a))>0)
j--;
if(i<j)
{
strcpy(temp,items[i].a); //swap the values at i and j'th index
strcpy(items[i].a,items[j].a);
strcpy(items[j].a,temp);
}
}
strcpy(temp,items[pivot].a);
strcpy(items[pivot].a,items[j].a);
strcpy(items[j].a,temp);
quicksort(items,first,j-1); //recursive call to quick sort
quicksort(items,j+1,last);
}
}
