Google Interview Question: Phone Interview: i) Find the ... | Glassdoor

Interview Question

Software Engineer Interview New York, NY

Phone Interview: i) Find the number of inversions in an

  array (describe & code) ii) Find collinear points in a given set of 2D points (describe & code)

Interview Answer

4 Answers


- Inversions is the number of changes required to make the array sorted.
- Use merge sort. While merging if value is picked from right array (that means the order was not correct initially) then increment the inversion counter
- Complexity O(nlgn)

deveffort on Jan 9, 2011

If the element was picked from the right array and there are still elements in the left array.

Victor on Jan 14, 2011

Collinear points:

Since two points are collinear, the task is to find all complete subsets of 3 or more collinear points, right?

v on Jan 19, 2011


Slight change, you need to not just increment the inversions, you need to add the number of elements remaining in the first part of the array.

sonofstars on Mar 29, 2012

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