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For simplicity, assume that n is a power of 2 (but, it is not needed in general). Suppose we are given a two dimensional integer

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For simplicity, assume that n is a power of 2 (but, it is not needed in general). Suppose we are given a two dimensional integer array A[1n,1n] in which every row is in nondecreasing order (from left to right) and also every column is in nondecreasing order (from top to bottom). Given such an A and an integer x, the problem is to determine if x is present in A : If x is present in A, the algorithm returns true; otherwise, it returns false. By comparing x to every entry in A, we can easily solve the problem in O(n2) time. We want to design a better algorithm using divide and conquer (even faster algorithms than the ones proposed here are possible, but the homework is about divide and conquer). (1) Let T(n) be the complexity of your algorithm when the input array A has n rows and n columns. Consider A divided into four quadrants as shown below: A=A1A3A2A4 Clearly, looking for x in A reduces to looking for x in each of A1,A2, A3, and A4 (each of which is a smaller and similar problem). Let us give names to these subproblems so that we can refer to them later: problem A1 : look for x in AI problem A2 : look for x in A2 problem A3 : look for x in A3 problem A4: look for x in A4 (a) ( 5 pts) Suppose we solve all the four smaller problems (recursively; by dividing into 4 subproblems, until we find x or we are left with problems of size one, and those are the base cases). Do you think this approach will give an algerithm with better complexity than O(n2) ? Justify your answer. There is no need to provide any algorithm

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