Problem30.java

package com.javamultiplex.projecteuler;

public class Problem30 {

	public static void main(String[] args) {

		int start = 2;
		/*
		 * Upper bound is 355000 because largest number that is generated by 6
		 * digits is 6*9^5 = 354294 so we can take more upper bound as 355000.
		 */
		int end = 355000;
		int sum = 0;
		for (int i = start; i <= end; i++) {
			if (canBeWrittenAsFifithPowerSum(i)) {
				sum += i;
			}
		}

		System.out.println(sum);
	}

	private static boolean canBeWrittenAsFifithPowerSum(int i) {

		// Converting int to String.
		String num = String.valueOf(i);
		String result = null;
		boolean valid = false;
		int length = num.length();
		int temp = 0, sum = 0;
		for (int j = 0; j < length; j++) {
			// Converting char to int.
			temp = num.charAt(j) - 48;
			sum += Math.pow(temp, 5);
		}
		// Converting int to String.
		result = String.valueOf(sum);
		if (result.equals(num)) {
			valid = true;
		}
		return valid;
	}

}