please can someone point out error in my logic of solving delivery man problem from codechef.::
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Sequence Motifs, Consensus Sequences and The Motif Finding Problem
Sequence Motifs and their Biological Significance
Sequence motifs are nucleic acid sequences that are widespread across or within a genomes and have or are speculated to have certain regulatory or structural biological functions.
Motifs that are found in different parts of the genomes like exons, introns and junk, have different functions. Motifs present in the exons ( coding part of the genome) decide the structure of the protein or label proteins to be sent to certain parts of the cell for processes like phosphorylation. Motifs that are present in introns (which makes up the non coding part of genome) are usually the regulatory sequences which determine the amount of gene expression and binding sites of proteins. Satellite DNA, which is the main component of centromeres and heterochromatin, is an example of motif found in junk parts of the genome.
A Detailed Description of DES and 3DES Algorithms (Data Encryption Standard and Triple DES)
While many ciphers have been created based upon the Feistel structure, the most famous of these is the Data Encryption Standard (DES). DES was based off of the original Lucifer cipher developed by Feistel and Coppersmith and submitted as an entry to the US National Bureau of Standards as a candidate for the US official encryption standard. After some modification (to improve security against differential cryptanalysis), it was selected and published as a standard in 1977.
Encryption with DES
The DES algorithm is a 16-round Feistel cipher. It takes as input a 64-bit input and a 64-bit secret key, and consists of three main stages:
The initial permutation
The round function (repeated 16 times)
The final permutation
A diagram of how these stages fit together with the ...
Motivation: Given an array of N numbers, you need to support two operations. Operation 1: find-min(i, j) = return the minimum value in array[i ... j]. Operation 2: update(i, v) = update the value at array[i] to v. Solve the problem for N <= 10^6, number of operations <= 10^6.
To solve the above problem, both the operations need to run in O(log N) time, but using an naive array gives O(N) run-time for operation 1 (and O(1) run-time for operation 2). So how do you solve the problem? Read on. :)
Video tutorial: This is a superb tutorial, giving the motivation, walking through example, and going step-by-step through the pseudocode.