@@ -402,19 +402,23 @@ private static int[] myMerge(int[] leftArray, int[] rightArray) {
402402 @ DivideAndConquer
403403 public static void quickSort (int [] array , int start , int end ) {
404404 if (end <= start ) return ; // base case
405- int pi = partition (array , start , end );
406- quickSort (array , start , pi - 1 );
407- quickSort (array , pi + 1 , end );
405+ int pivotIndex = partition (array , start , end );
406+ quickSort (array , start , pivotIndex - 1 );
407+ quickSort (array , pivotIndex + 1 , end );
408408 }
409409
410410 /**
411411 * @return index of pivot
412412 */
413413 public static int partition (int [] array , int start , int end ) {
414414 int pivot = array [end ]; // Pick pivot point
415+ 416+ // Index of smaller element and indicates
417+ // the right position of pivot found so far
415418 int i = start - 1 ;
416419
417420 for (int j = start ; j <= end - 1 ; j ++) {
421+ // If current element is smaller than the pivot
418422 if (array [j ] < pivot ) {
419423 i ++;
420424 array [j ] = Utils .gSwap (array [i ], array [i ] = array [j ]);
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