You have an array of n elements. Suppose you implement quicksort by always choosing the central element of the array as the pivot. Then the tightest upper bound for the worst case performance is

Which one of the following correctly determines the solution of the recurrence relation with T(1) = 1?
T(1) = 2T (n/2) + log n

Let P be a QuickSort Program to sort numbers in ascending order using the first element as pivot. Let t₁ and t₂ be the number of comparisons made by P for the inputs {1, 2, 3, 4, 5} and {4, 1, 5, 3, 2} respectively. Which one of the following holds?

Which of the following statement(s) is / are correct regarding Bellman-Ford shortest path algorithm?
P: Always finds a negative weighted cycle, if one exist s.
Q: Finds whether any negative weighted cycle is reachable from the source.