import java.util.Scanner;
public class SelectionSort {
void sort (int arr[])
{
int length = arr.length;
int min_idx=0; int temp_val=0;
for (int i = 0; i < length-1; i++)
{
min_idx=i;
for(int j=i; j<length; j++) {
if(arr [j] <arr [min_idx]){
min_idx=j;
}
}
temp_val arr
;
arr =arr[min_idx];
arr [min_idx]=temp_val;
System.out.flush("Ronnd %d :", i+1);
for(int j = 0; j<length; j++) {
System.out.print(arr[j]);
System.out.print(" ");
}
System.out.println();
}
}
public static void main(String args[])
{
SelectionSort ob = new SelectionSort();
System.out.print("Please input data size :");
Scanner scan = new Scanner(System.in); {
int num scan.nextInt();
int[] array = new int[num];
System.out.print("input data :");
for (int i=0; i<num; i++)
{
array=scan.nextInt();
}
}
}
} 
ช่วยอธิบายโค้ดนี้หน่อยครับว่าจะเอาไปพรีหน้าชั้น
public class SelectionSort {
void sort (int arr[])
{
int length = arr.length;
int min_idx=0; int temp_val=0;
for (int i = 0; i < length-1; i++)
{
min_idx=i;
for(int j=i; j<length; j++) {
if(arr [j] <arr [min_idx]){
min_idx=j;
}
}
temp_val arr ;
arr =arr[min_idx];
arr [min_idx]=temp_val;
System.out.flush("Ronnd %d :", i+1);
for(int j = 0; j<length; j++) {
System.out.print(arr[j]);
System.out.print(" ");
}
System.out.println();
}
}
public static void main(String args[])
{
SelectionSort ob = new SelectionSort();
System.out.print("Please input data size :");
Scanner scan = new Scanner(System.in); {
int num scan.nextInt();
int[] array = new int[num];
System.out.print("input data :");
for (int i=0; i<num; i++)
{
array=scan.nextInt();
}
}
}
}