Java Factorial factorialCheckBounds(int n)

Description

Compute n!

License

Open Source License

Parameter

Parameter	Description
n	a parameter

Exception

Parameter	Description
Exception	when the result exceeds Integer#MAX_VALUE

Return

the integer (not long value of) n factorial

Declaration

public static int factorialCheckBounds(int n) throws Exception 

Method Source Code

//package com.java2s;
/*//from   www .ja v  a  2s.  c o m
 *  Java Information Dynamics Toolkit (JIDT)
 *  Copyright (C) 2012, Joseph T. Lizier
 *  
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *  
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *  
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

public class Main {
    /**
     * Compute n! (n factorial), but check if this causes integer overflow
     * 
     * @param n
     * @return the integer (not long value of) n factorial
     * @throws Exception when the result exceeds {@link Integer#MAX_VALUE}
     */
    public static int factorialCheckBounds(int n) throws Exception {
        // TODO I'm not convinced this is safe. Should just hard-code the limit.
        long result = 1;
        for (int i = 1; i <= n; i++) {
            result *= (long) i;
            if (result > Integer.MAX_VALUE) {
                throw new Exception("n! causes integer overflow");
            }
        }
        return (int) result;
    }
}

Related

1. factorial(long l)
2. factorial(long n)
3. factorial(long num)
4. factorialAsDouble(int n)
5. factorialAsDoubleIncludeDivisor(int n, double divisor)
6. factorialDouble(final int n)
7. factorialLog(final int n)
8. factorialLog(final int n)