Ovi bhai link

http://jahid.info/

fibonacci number

Fibonacci sequence is a sequence of numbers defined by f1 = 1 f2 = 1 fn = fn-1 + fn-2

First ten terms 1, 1, 2, 3, 5, 8, 13, 21, 34, 55

JAVA CODE:

public int fib(int n) {

if (n <= 2)
return 1;
else
return fib(n - 1) + fib(n - 2)

}

Greatest Common Divisor/LCM


//gcd

public static long gcd(long a, long b) {

if (b==0)
return a;
else
return gcd(b, a % b);
}

//lcm

public long lcm(long a,long b){

return ((a*b)/gcd(a,b));
}

.

isprime

private boolean isPrime (int number)
{
  if (number<=1) return false;
  if (number==2) return true;
  if (number%2==0) return false;
  int boundary_no=(int)Math.round(Math.sqrt(number));

  for (int i=3; i<= boundary_no; i+=2)
     if (n%i==0)
        return false;

  return true;
}

swap two variables without temporary variable

x=5;
y=7;
x=x+y=5+7=12;
y=x-y=12-7=5;
x=x-y=12-5=7;

x=7;
y=5;

very silly?

Data Structure and algoritm link

http://www.algolist.net/