/* Overall test of arrays, loops, etc. that does a simple quicksort */

class Record {
   int a;
   void print() {
      write(a); 
      writeln();
   }
}

class Main {
   Record [] a;
   int i;

   void swap(Record r1, Record r2) {
      int temp;
   
      temp = r1.a;
      r1.a = r2.a;
      r2.a = temp;
   }
   
   void sort(int left, int right) {
      int i,j;
      int m;
      
      m = (a[left].a + a[right].a) / 2;
      i = left; 
      j = right;
      while (i <= j) {
         while (a[i].a < m) { i = i+1; }
         while (a[j].a > m) { j = j-1; }
         if (i <= j) {
            swap(a[i], a[j]);
            i = i + 1;
            j = j - 1;
         }
      }
      if (left < j) { sort(left, j); }
      if (i < right) { sort(i, right); }
   }
   
   void main() {
   
      int SIZE;        
      int j;

      SIZE = 5;
      
      a = new Record[SIZE];
      j = 0;
      while (j < SIZE) {
         a[j] = new Record();
         j = j + 1;
      }
      a[0].a = 5; 
      a[1].a = 3; 
      a[2].a = 1; 
      a[3].a = 4; 
      a[4].a = 2;
      
      /* Numbers before sorting */
      j = 0;
      while (j < SIZE) {
         a[j].print();
         j = j + 1;
      }
      writeln();
      
      sort(0, 4);
      
      /* Numbers after sorting */
      j = 0;
      while (j < SIZE) {
         a[j].print();
         j = j + 1;
      }
      writeln();
      
   }
}