#P15572. [USACO26FEB] Swap to Win B
[USACO26FEB] Swap to Win B
题目描述
Farmer John has a favorite string with characters. He also has strings each with characters ().
FJ can perform the following two types of operations:
- FJ chooses any string and two indices and . Then, he swaps the 'th and 'th character of ().
- FJ chooses two strings and and an index . Then, he swaps the 'th characters of and ().
His goal is to make equal to . Find any series of operations that fulfills his goal. Because FJ is in a hurry, he only has time to perform a total of operations. The inputs guarantee that it is possible to fulfill FJ's goal.
输入格式
The first line contains (), the number of independent tests. Each test is specified in the following format:
The first line contains and .
The second line contains .
Then, lines follow, the 'th of which contains .
The inputs will guarantee that it is possible to fulfill FJ's goal. All strings contain lowercase English letters (a-z).
输出格式
The output for each test should be as follows: On the first line, output an integer , the number of operations you will perform. must be a non-negative integer less than or equal to .
Then, output lines, denoting the operations you will perform in sequential order. Each line should be one of the following:
3
3 6
banana
nabana
banana
nnbaaa
5 3
abc
def
bca
ghi
jkl
mno
3 5
abcde
abcde
abcde
zzzzz
3
2 1 2 1
1 1 3 5
2 1 2 5
5
1 2 1 3
2 1 2 1
1 2 2 3
2 1 2 2
2 1 2 3
0
提示
Here is how changes according to the first test's output (with letters swapped in uppercase):
nabana Babana baNaBa banaNa
banana -> Nanana -> nanana -> nanaBa
nnbaaa nnbaaa nnbaaa nnbaaa
After all three operations, .
SCORING:
- Inputs 2-6:
- Inputs 7-12: No additional constraints.
Problem credits: Chongtian Ma