Question: in Twenty Lectures on Algorithmic Game Theory problem 4 . 2 d I can't find an example to show that the algorithm with the parameter

in Twenty Lectures on Algorithmic Game Theory problem 4.2 d I can't find an example to show that the algorithm with the parameter m set as in (a) and (b) need not yield a monotone allocation rule * the vi are rounded up can i get a numbered example? Problem 4.2 Section 4.2.2 gives an allocation rule for knapsack auctions that is monotone, guarantees at least 50% of the maximum social welfare, and runs in polynomial time. Can we do better? We first describe a classical fully polynomial-time approximation scheme (FPTAS) for the knapsack problem. The input to the problem is item values v_1,..., v_n, item sizes w_1,..., w_n, and a knapsack capacity W. For a user-supplied parameter >0, we consider the following algorithm _ ; m is a parameter that will be chosen shortly. - Round each v_i up to the nearest multiple of m, call it v_i^'.- Divide the v_i^''s through by m to obtain integers _1,...,_n.- For item values _1,...,_n, compute the optimal solution using a pseudopolynomial-time algorithm. [You can assume that there exists such an algorithm with running time polynomial in n and max _i=1^n_i.](a) Prove that if we run algorithm _ with the parameter m set to (max _i=1^n v_i)/ n, then the running time of the algorithm is polynomial in n and 1/(independent of the v_i 's).(b)(H) Prove that if we run algorithm _ with the parameter m set to (max _i=1^n v_i)/ n, then the algorithm outputs a solution with total value at least 1- times the maximum possible. (c) Prove that if we run algorithm _ with the parameter m set to a fixed constant, independent of the v_i 's, then the algorithm yields a monotone allocation rule. (d) Prove that if we run algorithm _ with the parameter m set as in (a) and (b), then the algorithm need not yield a monotone allocation rule. (e)(H) Give a DSIC mechanism for knapsack auctions that, for a user-specified parameter and assuming truthful bids, outputs an outcome with social welfare at least 1- times the maximum possible, in time polynomial in n and 1/.

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