Red-Green-Code

UVa 108 is rated as a Level 1 (easy) problem by uHunt, but its solution nevertheless contains some interesting techniques. Here’s a summary of the problem statement: Given an $N \times N$ array $A$ of positive and negative integers, print the sum of the nonempty subarray of $A$ that has the maximum sum. The sum […]

Last week, I wrote about the concept of mental representations, an important topic in Peak by Anders Ericsson and Robert Pool. According to the authors, learners seeking expertise should have as their goal a virtuous cycle between mental representations and deliberate practice: Deliberate practice should produce more effective mental representations, and more effective mental representations […]

Two weeks ago, I introduced the concept of memoization for dynamic programming, using as an example UVa 787. That problem involves operations on a sequence of integers, a one-dimensional structure. UVa 10755: Garbage Heap increases the problem complexity by organizing its integer data into a three-dimensional shape, a rectangular parallelepiped. Nevertheless, we can use memoization […]

In programming contests, some algorithms and techniques get more emphasis than they do in school or in professional programming work. One such technique is dynamic programming. CP3 has this to say about dynamic programming: This technique was not known before 1940s, nor frequently used in ICPCs or IOIs before mid 1990s, but it is considered […]