On the Average Difference between the Solutions to Linear and Integer Knapsack Problems

We analyze the expected difference between the solutions to the integer and linear versions of the 0–1 Knapsack Problem. This difference is of interest partly because it may help understand the efficiency of a well-known fast backtracking algorithm for the integer 0–1 Knapsack Problem. We show that, under a fairly reasonable input distribution, the expected difference is 0(log2n/n); for a somewhat more restricted subclass of input distribution, we also show that the expected difference is Ω(l/n).