25 人解决，32 人已尝试。
28 份提交通过，共有 52 份提交。
4.1 EMB 奖励。
单点时限: 2.0 sec
内存限制: 256 MB
Let‘s consider the sequence of digits from 1 through N (where N=9) in increasing order: 1 2 3 … N. Now insert either a '+' for addition or a '-' for subtraction or a ' ' [blank] to run the digits together, between each pair of digits (not in front of the first digit). Calculate the result that of the expression and see if you get zero.
Write a program that will find all sequences of length N that produce a zero sum.
The first line of the input contains the number of test cases (<10). Single test case is represented by single line that contains the integer N (3 <= N <= 9).
For each test case in ASCII order, print each sequence that can create 0 sum with a '+', '-', or ' ' (space) between each pair of numbers. Space shows that the digits run together. Different test cases should be separated by an empty line.
2 3 7
1+2-3 1+2-3+4-5-6+7 1+2-3-4+5+6-7 1-2 3+4+5+6+7 1-2 3-4 5+6 7 1-2+3+4-5+6-7 1-2-3-4-5+6+7
25 人解决，32 人已尝试。
28 份提交通过，共有 52 份提交。
4.1 EMB 奖励。