Check if a number is Fibonacci

A Fibonacci number is one which appears in the Fibonacci Sequence. To check if a given number n occurs in the Fibonacci Sequence or not we only need to check if one or both of (5*n^2 + 4) or (5*n^2 – 4) is a perfect square or not (source: wiki). Python code for the same: ...

Pascal Triangle in C

Pascal Triangle in C
The following C code generates on standard output a Pascal Triangle as specified on this wiki page. Specifically output in following format is generated: C /* The following code is used to print the Pascal triangle for as many rows as input by the user. */ #include<stdio.h> // begin the main function for this program ...

Code Jam Cookie Clicker Alpha

This is a solution to the Code Jam 2014 Qualification Round problem B, Cookie Clicker Alpha. (Problem Description Link) Python __author__ = 'Coddicted' def read_case(inf): return inf.readline().split(' ') def write_case(f, i, res): f.write('Case #%d: '%i) f.write('%.7f'%res) f.write('\n') def main(): with open('data_files/B-large-practice.in', 'r') as inf, open('data_files/B-large-practice.out', 'w') as of: t = int(inf.readline()) case_cnt = 1 while ...

Code Jam Magic Trick

Code Jam Magic Trick
This is the solution to Code Jam 2014 qualification round problem A. Magic Trick. (Problem Link) Python __author__ = 'Coddicted' def read_row(inf):     return inf.readline().strip().split(' ') def main():     with open('data_files/A−small−practice.in', 'r') as inf, open('data_files/A−small−practice.out', 'w') as of:         t = int(inf.readline())         case_cnt = 1         while case_cnt <= t:             row = int(inf.readline())             i = 1             row1 = []             while i <= 4:                 if i == row:                     row1 = read_row(inf)                 else:                     inf.readline()                 i += 1             row = int(inf.readline())             row2 = []             i = 1             while i <= 4:                 if i == row:                     row2 = read_row(inf)                 else:                     inf.readline()                 i += 1             row1 = [int(item) for item in row1]             row2 = [int(item) for item in row2]             comm = [item for item in row1 if item in row2]             if len(comm) == 1:                 of.write('Case #' + str(case_cnt) + ': ' + str(comm[0]) + '\n')                 print 'Case #' + str(case_cnt) + ': ' + str(comm[0])             elif len(comm) > 1:                 of.write('Case #' + str(case_cnt) + ': ' + 'Bad magician!' + '\n')                 print 'Case #' + str(case_cnt) + ': ' + 'Bad magician!'             else:                 of.write('Case #' + str(case_cnt) + ': ' + 'Volunteer cheated!' + '\n')                 print 'Case #' + str(case_cnt) + ': ' + 'Volunteer cheated!' ...

To compare two folders (recursively) in Java 21

Java package com.example; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.security.MessageDigest; import java.util.Arrays; import java.util.HashMap; import java.util.Iterator; import java.util.Set; public class Compare { //This can be any folder locations which you want to compare File dir1 = new File("C:\\ComparisonFolder\\master"); File dir2 = new File("C:\\ComparisonFolder\\release"); public static void main(String ...args) { Compare compare = ...

Count Triangles in a Graph 1

The following code implementation counts the number of triangles present in a graph G. For graph representation JUNG API is used but can be extended/ changed to use any other notation by simple means. Java import java.util.Collection; import java.util.HashSet; import java.util.Iterator; import edu.uci.ics.jung.graph.Graph; public class TriangleFinder { private Graph<Integer, String> g; /** * @return The ...

Dijkstra’s Algorithm : Finding all possible shortest paths between two vertices in a graph 4

Dijkstra's Algorithm : Finding all possible shortest paths between two vertices in a graph
The following code implements the Dijkstra’s Shortest Path Algorithm and further extends is to get all possible shortest paths between two vertices. For graph representation we make use of JUNG API, its usage, however, is primarily in visualizing the graph and can be extended easily for any other representation as well. Random Graph Generator code ...

Code for Random Graph Generation G(n,p) 1

Code for Random Graph Generation G(n,p)
Following is the Java code for generating a Random Graph G(n, p) where ‘n’ is the number of nodes/ vertices in the graph and ‘p’ is the probability that any edge will form or not. The code makes use of JUNG API for graph visualization and creation. More About JUNG… Java import java.awt.Dimension; import javax.swing.JFrame; ...

ConcurrentHashMap 1

ConcurrentHashMap
Javadoc says… “A hash table except supporting full concurrency of retrievals and adjustable expected concurrency for updates. This class obeys the same functional specification as Hashtable, and includes versions of methods corresponding to each method of Hashtable. However, even though all operations are thread-safe, retrieval operations do not entail locking, and there is not any ...

Matlab code to create k-connected Harary Graph 4

Matlab code to create k-connected Harary Graph
The following is a MATLAB script to create a k-connected Harary Graph of n-nodes. Clearly the inputs required are n (no of nodes) and k (degree of each node). Also, while the code is a MATLAB script the basic technique to generate the adjacency matrix of the graph can be easily adopted to other languages ...