Solution:
Selection Sort:
In this sorting algorithm the list is divided into two parts. The left part is sorted and right part of the list is unsorted. The smallest element compared to all remaining elements and swapped with that element.
In this sorting technique, the first element compared to all the element and finding the minimum element and replace it to left side of array.
Program
#include <stdio.h>
#include <string.h>
#define max 100
struct nick
{
char a[20];
};
//function for selection sort
void selection(struct nick items[], int);
int main()
{
FILE *fp; //file pointer
int i=0,k=0,n;
char fname[20],str[20],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"); //opening file in write mode
for(i=0;i<n;i++)
{
scanf("%s",name);
fprintf(fp,"%s ",name); //writing it on file
}
fclose(fp);
i=0;
fp=fopen(fname,"r"); //opening file in read mode
while((c=getc(fp))!=EOF)
{
if(c==' ')
{
str[i]='\0';
strcpy(name[k].a,str);
i=0;
k++;
}
else
{
str[i]=c;
i++;
}
}
fclose(fp); //close file pointer
printf("\nInitial contents of file: \n");
for(i=0; i<k; i++)
printf("%s,", name[i].a); //printing initial contents
selection(name,k); //calling selection sort
printf("\n\nAfter applying selection sort: \n");
for(i=0; i<k; i++)
{
printf("%s,", name[i].a); //result after swapping
}
return 0;
}
void selection(struct nick items[], int n)
{
int i=0,j=0,pos=0;
char min[20];
char temp[10];
for(i=0;i<n-1;i++)
{
strcpy(min,items[i].a); //copy the items at i'th index in min
pos=i;
for(j=i+1;j<n;j++)
{
if(strcmp(min,items[j].a)>0)
{
strcpy(min,items[j].a);
pos=j;
}
}
if(pos!=i)
{
strcpy(temp,items[i].a); //swap item[pos] and item[i]
strcpy(items[i].a,min);
strcpy(items[pos].a,temp);
}
}
}
Output:
