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The problem: Given N computers, each has M numbers. Find median of all N*M numbers. Sometimes a master computer is used in the setting which...

See here for the following 3 methods: Method 1: similar to merge sort, the (m+n)/2-th element is median. O(m+n). Method 2: divide and conqu...

- A blog in Chinese on algorithms . - Another blog in Chinese . - Yet another blog in Chinese - Fast implementation of memcpy in C . - Imple...

Given a binary matrix M of 0s and 1s. 1) find the maximal square sub-matrix. 2) find the maximal sub-matrix. 1) is easy. The key is to setup...

Say we have two lists of numbers. The lists are equal in length but order of elements are not the same. How to find out if the two lists con...

The problem is to find the largest rectangle under a histogram. This question is the last question from 2003/2004 ACM International Colleg...

How do you evaluate a search engine such as google or bing? There is a field called IR (Information Retrieval) Evaluation that addresses thi...