Question: Given a sequence of integers X = x1, . . . , xn and a number k, find the longest k-zigzag subse- quence of X.
Given a sequence of integers X = x1, . . . , xn and a number k, find the longest k-zigzag subse- quence of X. The time of your DP algorithm should be O(kn2). A k-zigzag subsequence is one which alternates between being strictly increasing and being strictly decreasing at most k times. A 0-zigzag subsequence is just an increasing subsequence. A 1- zigzag subsequence is a subsequence which is increasing at first but then may change direction and become decreasing. A 2-zigzag subsequence is a sequence which is increasing at first and then may change direction at most twice. Similarly, a k-zigzag subsequence is a subsequence which starts as increasing but then it may change direction at most k times. For example, the subsequence 1,5,7,9,8,4 is a 1-zigzag as it is strictly increasing at first, up to 9, and then changes direction once and becomes strictly decreasing. For full credit, you should use the SRBTOT framework
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