Made easy test

Question

Comments

yeah ans is 48...but how 13 can be used as a pivot

---

Pivot element is nothing but the element to the

left of it all the elements should be <= pivot

and to the right should be > pivot

so elements to the right of 13 are 18,15,17,24 all are greater than 13 so it can be a pivot.

---

ok..got it

Answer 1

Observe that after one pass of quicksort the position of the pivot is same as the position of it in the sorted array.

Sort the array mentally it will be {6,9,11,13,15,17,18,24}

and the given array is {9,6,11,13,18,15,17,24}

So, you will get that that positions of 11,13 and 24 in the given array is same as in the sorted array.

After that check whether all the elements to the left of 11,13 and 24 are less than 11,13 and 24 or not respectively.

Also check whether all the elements to the right of 11,13 and 24 are greater than 11,13 and 24 or not respectively.

You will see that 11,13 and 24 passes this two tests so, 11,13 and 24 can be chosen as pivot.

Hence the answer is 11+13+24 = 48 (Answer)

Answer 2

After the first pass of the algorithm the pivot element should be in it's correct position i.e the number left to pivot should be smaller and the number right to pivot should be greater.

Hence only numbers 11, 13 and 24 follows above condition.

So sum of all values = 11 + 13 + 24 = 48.