
ZOJ Problem Set  2371
Consider the set of all nonnegative integer powers of 3. S = { 1, 3, 9, 27, 81, ... } Consider the sequence of all subsets of S ordered by the value of the sum of their elements. The question is simple: find the set at the nth position in the sequence and print it in increasing order of its elements. Input Each line of input contains a number n, which is a positive integer with no more than 19 digits. The last line of input contains 0 and it should not be processed. Output For each line of input, output a single line displaying the nth set as described above, in the format used in the sample output. Sample Input
1 Sample Output
{ } Source: University of Waterloo Local Contest 2004.06.12 