Difficulity：
N/A
| Test Data Sets: 1 (Hidden) | Judging:
Traditional Judge

Accepted : 2 Times | Submit :11 Times | Clicks : 350

Accepted ： 1 Users | Submit : 1 Users | Accepted rate : 100%

Time Limit ：10000 ms | Memory Limit : 64000 KBytes

Update : 2012-10-29 17:19

Accepted : 2 Times | Submit :11 Times | Clicks : 350

Accepted ： 1 Users | Submit : 1 Users | Accepted rate : 100%

Time Limit ：10000 ms | Memory Limit : 64000 KBytes

Update : 2012-10-29 17:19

The Circular Intelligence Agency stores all secret information in the following circular codes. Each encrypted string is an N-bit binary string c = c_{0}c_{1 ... }c_{N-1}. We say that binary string a = a_{0}a_{1 ... }a_{N-1 }is a circular rotation of c if there exists an index k with 0 ≤ k ≤ N - 1 such that c_{i }= a_{(i+k) mod N} holds for each i =0, 1, ... , N - 1. The message d = d_{0}d_{1 ... }d_{N-1} to be decrypted is the bit-wise exclusive-OR of a = a_{0}a_{1 ... }a_{N-1} and b = b_{0}b_{1 ... }b_{N-1}, where

- a is the circular rotation of c such that the binary number represented by a (if treated as a nonnegative integer) is the maximum, and
- b is the circular rotation of c such that the binary number represented by b (if treated as a nonnegative integer) is the minimum.

For instance, if c = 11001, then a = 11100, b = 00111, and d = 11011.

- 1 ≤ N ≤ 300000

**
Input：**

In the rst line of the input le there is an integer C, indicating the number

of distinct test cases to be followed. Each of the next C lines stands for a

test case. For each test case, there is an integer N, followed by an N-bit

binary string.

**
Output：**

Output should be C lines. The binary string in the j-th line is the decrypted

message for the j-th test case.

**
Sample Input：**

若題目沒有特別說明，則應該以多測資的方式讀取，若不知如何讀取請參考 a001 的範例程式。

5 5 10101 6 111111 7 0000000 6 110110 25 1101001011100100111010101

**
Sample Output
：**

10001 000000 0000000 101101 1100110110111110001110011

**
Hint
：**

**
Author
：**

C |
C++ |
JAVA |
PASCAL |
---|---|---|---|

46206. rabbit125 (184ms, 1616KB, 851B) |
|||

Program running time may be affected by various factors. Check server system environment information here