Function not working on c program selection sort - c

Question

Why this function is not working here? It's not sorting on output.
Suppose if I enter 1 4 2 the output is always 1 4 2 not 1 2 4.
How can properly implement this selection sort?
Thanks in advance!!
#include <stdio.h>
int selection_sort (int a[],int n, int i, int j,int temp,int min){
for(i=0;i<n;i++)
scanf("%d",&a[i]);
for(i=0;i<n;i++){
min=i;
for(j=i+1;j<n;j++){
if(a[j]<a[min]){
min=j;
}
}
temp=a[i];
a[i]=a[min];
a[min]=temp;
}
}
int main(){
int i, j, n,a[20], temp,min;
printf("How many elements:\n ");
scanf("%d",&n);
printf("Enter array elements:\n");
for(i=0;i<n;i++)
scanf("%d",&a[i]);
printf("Sorted array: ");
for(i=0;i<n;i++)
printf(" %d",a[i]);
return 0;
selection_sort(i,j,n,a,temp,min);
}

Answer 1

There are 3 main issues in your code:
You are getting user input twice. One in main function:
printf("Enter array elements:\n");
for(i=0;i<n;i++)
scanf("%d",&a[i]);
Another in selection_sort function:
for(i=0;i<n;i++)
scanf("%d",&a[i]);
Fix this by removing the one in selection_sort function.
As noted in the comments section, you are returning from main function before calling selection_sort function:
return 0;
Fix this by moving it to the end of main function.
You are printing the expected results from selection_sort function before calling it:
printf("Sorted array: ");
for(i=0;i<n;i++)
printf(" %d",a[i]);
...
selection_sort(i,j,n,a,temp,min);
Fix this by calling selection_sort before printing its results.
Here is the fixed code:
#include <stdio.h>
int selection_sort (int a[], int n, int i, int j, int temp, int min)
{
for(i=0;i<n;i++) {
min=i;
for(j=i+1;j<n;j++) {
if(a[j]<a[min]) {
min=j;
}
}
temp=a[i];
a[i]=a[min];
a[min]=temp;
}
}
int main()
{
int i, j, n,a[20], temp, min;
printf("How many elements: ");
scanf("%d",&n);
printf("Enter array elements: ");
for(i=0;i<n;i++) {
scanf("%d",&a[i]);
}
selection_sort(a, n, i, j, temp, min);
printf("Sorted array:");
for(i=0;i<n;i++) {
printf(" %d", a[i]);
}
printf("\n");
return 0;
}
Here is a test:
$ gcc main.c && ./a.out
How many elements: 3
Enter array elements: 1 4 2
Sorted array: 1 2 4

Answer 2

int main(){
int i, j, n,a[20], temp,min;
printf("How many elements:\n ");
scanf("%d",&n);
printf("Enter array elements:\n");
for(i=0;i<n;i++)
scanf("%d",&a[i]);
selection_sort(a,n,i,temp,min);//Not need to use j,cause j isn't used in your function
for(i=0;i<n;i++)
printf("%d\t",a[i]);//You should call your function before print your data,and also before "return 0"
return 0;
}
AND,"int i,int temp,int min" these don't need to be the parameters.You can just create them in your function