public static void selSort(int[] arr){
 
  int length = arr.length;
  
  for(int i = 0; i<length-1; i++){
    
    int index = i;
    
    for(int j = i+1; j < length; j++){
      if(arr[j]<arr[index])
	index = j;
    }
    // p1
    swap(arr,i,index);
    // p2
  }
  
}

public static void swap(int[] arr, int i, int j){
  
  int tmp = arr[i];
  arr[i] = arr[j];
  arr[j] = tmp;
}