Given a list of bash commands to manipulate folders/files. Can you answer the results of a list of existence checking?
Suppose we are under the empty root folder ‘/’. The commands include: mkdir [-p], touch and rm [-r], which are all BSD general commands. If you are not familiar with them, refer to command explanations (备注) after the output example. If the command cannot be executed correctly, just ignore this command.
The questions are existFile or existFolder, which are described as below. A valid path can either be a file or folder, not both.
existFile path
Check whether a file specified by path exists. Output ‘true’ if file exists, ‘false’ otherwise. existFolder path Check whether a folder specified by path exists. Output ‘true’ if folder exists, ‘false’ otherwise.
输入描述:
The first line contains two integers m(1 
m 1000) and n((1 n 100) – the number of commands and questions separately.The following m lines are the commands, followed by n lines of questions.
输出描述:
For each question, output “true” if the file/folder
exists or “false” otherwise.
示例1
输入
4 2
mkdir -p a/b/c
mkdir a/b/c/d/e
touch file1
rm -r a/b
existFolder /a/b
existFile /file1
说明
1. We are in root folder ‘/’.
2. ‘/’ at the beginning of each path is optional.
3.Multiple sequential '/' is equal to one '/'.
4. The path string will only contain alphabetic characters, numbers, '_' or '/'.
5. Command options, -p and -r, will always occur before path string it they exist and there will only be one path string for each command.
备注:
NAME
mkdir -- make directories
SYNOPSIS
mkdir [-p] directory_name
DESCRIPTION
The mkdir utilitycreates the directories named as operands.
The options areas follows:
-p Create intermediatedirectories as required. If this optionis not specified, the full path prefix of each operand must already exist. On the other hand, with this optionspecified, no error will be reported if a directory given as an operand alreadyexists.
NAME
touch -- change file access andmodification times
SYNOPSIS
touch file
DESCRIPTION
The touch utility sets themodification and access times of files. If any file does not exist, it is created with default permissions.
NAME
rm -- remove directory entries
SYNOPSIS
rm [-r] file
DESCRIPTION
The rm utility attempts to remove the non-directory type filesspecified on the command line.
The options are as follows:
-r Attempt to remove the file hierarchyrooted in the file argument. The -roption implies the -d option.
