题目描述
Problem Statement
You are given integers N,\ A and B.
Determine if there exists a permutation (P_0,\ P_1,\ ...\ P_{2^N-1}) of (0,\ 1,\ ...\ 2^N-1) that satisfies all of the following conditions, and create one such permutation if it exists.
- P_0=A
- P_{2^N-1}=B
- For all $0 \leq i < 2^N-1$, the binary representations of P_i and P_{i+1} differ by exactly one bit.
Input
Input is given from Standard Input in the following format:
N A B
Output
If there is no permutation that satisfies the conditions, print NO.
If there is such a permutation, print YES in the first line.
Then, print (P_0,\ P_1,\ ...\ P_{2^N-1}) in the second line, with spaces in between.
If there are multiple solutions, any of them is accepted.
Constraints
- $1 \leq N \leq 17$
- $0 \leq A \leq 2^N-1$
- $0 \leq B \leq 2^N-1$
- $A \neq B$
- All values in input are integers.
Sample Input 1
2 1 3
Sample Output 1
YES
1 0 2 3
The binary representation of P=(1,0,2,3) is (01,00,10,11), where any two adjacent elements differ by exactly one bit.
Sample Input 2
3 2 1
Sample Output 2
NO
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分