1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/Collatz.java	Tue Oct 18 01:17:49 2011 -0700
     1.3 @@ -0,0 +1,37 @@
     1.4 +package coderloop;
     1.5 +
     1.6 +import java.io.File;
     1.7 +import java.util.Scanner;
     1.8 +
     1.9 +class Collatz {
    1.10 +    public static void main(String[] args)throws java.io.FileNotFoundException{
    1.11 +	File file = new File(args[0]);
    1.12 +	Scanner scanner = new Scanner(file);
    1.13 +	int n = scanner.nextInt();
    1.14 +	System.out.println(search_collatz(n));}
    1.15 +    
    1.16 +    public static long collatz_next(long n){
    1.17 +	if (0 == (n % 2)){
    1.18 +	    return n/2;}
    1.19 +	else {
    1.20 +	    return (1 + (n * 3));}}
    1.21 +    
    1.22 +    public static int collatz_length(int n){
    1.23 +	long t = n;
    1.24 +	int d = 1;
    1.25 +	while (t > 1){
    1.26 +	    t = collatz_next(t);
    1.27 +	    d++;}
    1.28 +	return d;}
    1.29 +    
    1.30 +    public static int search_collatz(int n){
    1.31 +	int max = 0;
    1.32 +	int max_val = 0;
    1.33 +	int temp_val = 0;
    1.34 +	for (int i = 1; i<n; i++){
    1.35 +	    temp_val = collatz_length(i);
    1.36 +	    if (temp_val > max_val){
    1.37 +		max = i;
    1.38 +		max_val = temp_val;}}
    1.39 +	return max;}
    1.40 +}