Project Euler 36

原题：

The decimal number, 585 = 1001001001 (binary), is palindromic in both bases.
 Find the sum of all numbers, less than one million, which are palindromic in base 10 and base 2.
(Please note that the palindromic number, in either base, may not include leading zeros.)

分析：

利用java的Integer.toBinaryString(10)方法，将十进制转化为二进制。

public class Problem36 {//判断是否为回文数。static boolean isReverseNumber(String numberStr){int length = numberStr.length();for(int i=0;i<length-1/2;i++){if(numberStr.charAt(i) != numberStr.charAt(length-i-1))return false;}return true;}public static void main(String[] args) {//System.out.println(Integer.toBinaryString(10)); 10-2//System.out.println(Integer.valueOf("1010", 2)); 2-10long beginTime = System.currentTimeMillis();int count = 0;for(int i=999999;i>0;i=i-2){if(isReverseNumber(String.valueOf(i))&&isReverseNumber(Integer.toBinaryString(i))){System.out.print(i+" -- ");System.out.print(Integer.toBinaryString(i));System.out.println();count += i;}}System.out.println("count:"+count);//872187long endTime = System.currentTimeMillis();System.out.println(endTime - beginTime +"ms");}}