Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
//License from project: Open Source License 

public class Main {
    public static int[] primeFactorization(int i) {
        if (i < 0) {
            throw new ArithmeticException("Cannot determine if a negative value is prime");
        } else if (i == 0) {
            throw new ArithmeticException("Cannot determine if zero is prime");
        } else if (i == 1) {
            throw new ArithmeticException("Cannot determine if one is prime");
        } else {
            int[] returnValue = new int[i];
            int j = i;
            int x = 0;
            int n = 2;
            while (n <= j) {
                if (test(n)) {
                    if (j % n == 0) {
                        returnValue[x] = n;
                        x++;
                        j = j / n;
                        n = 1;
                    }
                }
                n++;
            }
            return arrayCopy(returnValue);
        }
    }

    public static boolean test(int i) {
        if (i < 0) {
            throw new ArithmeticException("Cannot determine if a negative value is prime");
        } else if (i == 0) {
            throw new ArithmeticException("Cannot determine if zero is prime");
        } else if (i == 1) {
            throw new ArithmeticException("Cannot determine if one is prime");
        } else if (i == 2) {
            return true;
        } else {
            return unprotectedTest(i);
        }
    }

    public static boolean test(long l) {
        if (l < 0) {
            throw new ArithmeticException("Cannot determine if a negative value is prime");
        } else if (l == 0) {
            throw new ArithmeticException("Cannot determine if zero is prime");
        } else if (l == 1) {
            throw new ArithmeticException("Cannot determine if one is prime");
        } else if (l == 2) {
            return true;
        } else {
            return unprotectedTest(l);
        }
    }

    public static int[] test(int[] intArray) {
        int[] returnArrayTemp = new int[intArray.length];
        for (int n = 0, m = intArray.length; n < m; n++) {
            int i = intArray[n];
            if (i < 0) {
                throw new ArithmeticException("Cannot determine if a negative value is prime");
            } else if (i == 0) {
                throw new ArithmeticException("Cannot determine if zero is prime");
            } else if (i == 1) {
                throw new ArithmeticException("Cannot determine if one is prime");
            } else if (i == 2) {
                returnArrayTemp[n] = i;
            } else {
                if (unprotectedTest(i) == true) {
                    returnArrayTemp[n] = i;
                }
            }
        }
        int[] returnArray = arrayCopy(returnArrayTemp);
        return returnArray;
    }

    private static int[] arrayCopy(int[] x) {
        int z = 0;
        int[] l = new int[x.length + 1];
        for (int i = 0; i < x.length; i++) {
            int y = x[i];
            if (y != 0) {
                l[z] = y;
                z++;
            }
        }
        int[] n = new int[z];
        System.arraycopy(l, 0, n, 0, z);
        return n;
    }

    private static boolean unprotectedTest(int i) {
        for (int n = 2, max = (int) Math.ceil(Math.sqrt(i)); n <= max; n++) {
            if (i % n == 0) {
                return false;
            }
        }
        return true;
    }

    private static boolean unprotectedTest(long l) {
        for (int n = 2, max = (int) Math.ceil(Math.sqrt(l)); n <= max; n++) {
            if (l % n == 0) {
                return false;
            }
        }
        return true;
    }
}