This can be done in O(N). Avoid sorting as it will be O(NlogN)
Here's one of many Q on how http://stackoverflow.com/questions/7272534/finding-the-first-n-largest-elements-in-an-array
This can be done in O(N). Avoid sorting as it will be O(NlogN)
Here's one of many Q on how http://stackoverflow.com/questions/7272534/finding-the-first-n-largest-elements-in-an-array