P1118 [USACO06FEB] Backward Digit Sums G/S
题目描述
`FJ` and his cows enjoy playing a mental game. They write down the numbers from $1$ to$ N(1 \le N \le 10)$ in a certain order and then sum adjacent numbers to produce a new list with one fewer number. They repeat this until only a single number is left. For example, one instance of the game (when $N=4$) might go like this:
```cpp
3 1 2 4
4 3 6
7 9
16
```
Behind `FJ`'s back, the cows have started playing a more difficult game, in which they try to determine the starting sequence from only the final total and the number $N$. Unfortunately, the game is a bit above `FJ`'s mental arithmetic capabilities.
Write a program to help `FJ` play the game and keep up with the cows.
输入格式
无
输出格式
无
说明/提示
- 对于 $40\%$ 的数据,$1\le n\le 7$;
- 对于 $80\%$ 的数据,$1\le n \le 10$;
- 对于 $100\%$ 的数据,$1\le n \le 12$,$1\le sum\le 12345$。