OpenJudge - 1565:Skew Binary

1565:Skew Binary

When a number is expressed in decimal, the kth digit represents a multiple of 10 k. (Digits are numbered from right to left, where the least significant digit is number 0.) For example,
81307(10) = 8 * 10^4 + 1 * 10 ^3 + 3 * 10^2 + 0 * 10^1 + 7 * 10^0
= 80000 + 1000 + 300 + 0 + 7
= 81307.

When a number is expressed in binary, the kth digit represents a multiple of 2^k . For example,

10011(2) = 1 * 2^4 + 0 * 2^3 + 0 * 2^2 + 1 * 2^1 + 1 * 2^0
= 16 + 0 + 0 + 2 + 1
= 19.

In skew binary, the kth digit represents a multiple of 2^(k+1)-1. The only possible digits are 0 and 1, except that the least-significant nonzero digit can be a 2. For example,

10120(skew) = 1 * (2^5-1) + 0 * (2^4-1) + 1 * (2^3-1) + 2 * (2^2-1) + 0 * (2^1-1)
= 31 + 0 + 7 + 6 + 0
= 44.

The first 10 numbers in skew binary are 0, 1, 2, 10, 11, 12, 20, 100, 101, and 102. (Skew binary is useful in some applications because it is possible to add 1 with at most one carry. However, this has nothing to do with the current problem.)
 

输入

The input contains one or more lines, each of which contains an integer n. If n = 0 it signals the end of the input, and otherwise n is a nonnegative integer in skew binary.

输出

For each number, output the decimal equivalent. The decimal value of n will be at most 2^31-1 = 2147483647.

斜二进制数
当一个数被表示为十进制数，每项的基数代表10的k次方。（数字被从右到左排序，最末的数是10的0次方）。例如，
81307(10) = 8 * 10^4 + 1 * 10 ^3 + 3 * 10^2 + 0 * 10^1 + 7 * 10^0= 80000 + 1000 + 300 + 0 + 7= 81307.
当一个数字被表示成二进制数，每项的基数代表2的k次方。例如，
10011(2) = 1 * 2^4 + 0 * 2^3 + 0 * 2^2 + 1 * 2^1 + 1 * 2^0= 16 + 0 + 0 + 2 + 1= 19.
在斜二进制数中，每项的基数代表2的k+1次方-1。可能的数字只有0和1，除了最低有效非零为可以为2。例如，
10120(skew) = 1 * (2^5-1) + 0 * (2^4-1) + 1 * (2^3-1) + 2 * (2^2-1) + 0 * (2^1-1)= 31 + 0 + 7 + 6 + 0= 44.
前十个数字用斜二进制数表示为0, 1, 2, 10, 11, 12, 20, 100, 101, 和102。（斜二进制数在一些应用中很有用因为它最多一次进位可以加1。然而，这对现在这道题来说没什么用。）
输入：
输入包括一行或者多行，每行包括一个整数n。如果n = 0代表输入结束，否则n是正斜二进制数。
输出：
对于每个数，输出等价十进制数。十进制的值n将最大为2^31-1 = 2147483647。