A 0-1 Knapsack Problem

/*
Input two integers M and N. Find all possible ways that the sum of numbers chosen from 1, 2,3,...N equals M. Print all possible combinations.
*/

Combination of letters

// List all combinations of letters in a string. Suppose no letter is repeated.
// traverse letters from the first one to the last one.
// combination[ ] is used to save the result of each combination.
// layer indicates the number of letters in the combination, also it tells you
// the position of the newly visited letter in combination[ ]
// layer increases by one in each recursion

Target Shooting Problem

Target shooting

Decimal Integer to Binary

Sieve of Eratosthen algorithm

Sieve of Eratosthen algorithm is used to find primes.
The following codes(modified) are from Algorithms in C++ and Core Java Volume I.

Palindrome

The following program determines if a given string is a palindrome.
Another way to do this is first to copy the string to another char[] and remove the non- alphabet characters from the string. Then copy it to the third char array and  reverse the order of the string . Finally compare the two strings.

[C++] An implementation of atoi

This is an implementation of atoi function I wrote. Seems it works.

Setup MySql on Ubuntu 11.04

Install MySQL

sudo apt-get install mysql-server-5.1
sudo mysql_install_db
sudo mysql_secure_installation

Then download and install JDBC (connector/J) driver.

MySQL Programming in Java

Connecting to Database:

String url = "jdbc:mysql://hostname:portNumber/databaseName";
String username = "dbuser";
String password = "secret";
Connection conn = DriverManager.getConnection(url, 
   username, password);

Setup MySQL on Fedora 15

yum install mysql-server

Start MySQL server and autostart on boot:

/etc/init.d/mysqld start  ## use restart after update
##OR##
service mysqld start ## use restart after update
chkconfig --levels 235 mysqld on