What's New -  November 2011




November 10, 2011:  If you are into search algorithms, here's one, Branch and Bound,  which demonstrates "Exhaustive" and "Branch and Bound" search methods for finding the best solution for "Knapsack" problems.  It was adapted with the author's kind permission from the book "Ready-to-Run Delphi 3.0 Algorithms", Rod Stephens, Wiley Computer Publishing. The Knapsack Problem requires that we figuratively fill a knapsack by selecting from a set of items whose weight (or other "cost" measurement) and value (or "profit") are known. The objective is to maximize the value (profit) of the items in the sack without exceeding a predefined weight (cost) limit.  The "Branch and Bound" method  is orders of magnitude faster than Exhaustive  search for large cases.



November 13, 2011:  Another  small feature upgrade for our Brute Force Solver program today.  In Brute Force Version 2.6, you can specify the allowed solution integers as a range ( for example. 1-5 instead of 1,2,3,4,5.    Today's Mensa Calendar Puzzle "Alphametics" problem is also included in the sample problem download files as a test case..  Just enter NOW+NOW+NO=CHOW into the program to find the answer. 

November 30, 2011:  The  Four Fours problem requires that digits 4444 be combined with mathematical operations to form expressions which evaluate to all values from 0 to 100.  I couldn't do it using +,-,*,/,^ operations (other "cheats" are required).  I did generalize the problem so that my Four Fours version does find 4 digit solutions for smaller target ranges or 5 digit solutions for all 101 targets..