1166 Design File System

You are asked to design a file system that allows you to create new paths and associate them with different values.

The format of a path is one or more concatenated strings of the form: /followed by one or more lowercase English letters. For example, "/leetcode" and "/leetcode/problems" are valid paths while an empty string "" and "/" are not.

Implement the FileSystem class:

• bool createPath(string path, int value) Creates a new path and associates a value to it if possible and returns true. Returns false if the path already exists or its parent path doesn't exist.
• int get(string path) Returns the value associated with path or returns -1 if the path doesn't exist.

Example 1:

Input: 
["FileSystem","createPath","get"]
[[],["/a",1],["/a"]]
Output: 
[null,true,1]
Explanation: 
FileSystem fileSystem = new FileSystem();

fileSystem.createPath("/a", 1); // return true
fileSystem.get("/a"); // return 1

Example 2:

Input: 
["FileSystem","createPath","createPath","get","createPath","get"]
[[],["/leet",1],["/leet/code",2],["/leet/code"],["/c/d",1],["/c"]]
Output: 
[null,true,true,2,false,-1]
Explanation: 
FileSystem fileSystem = new FileSystem();

fileSystem.createPath("/leet", 1); // return true
fileSystem.createPath("/leet/code", 2); // return true
fileSystem.get("/leet/code"); // return 2
fileSystem.createPath("/c/d", 1); // return false because the parent path "/c" doesn't exist.
fileSystem.get("/c"); // return -1 because this path doesn't exist.

Constraints:

• 2 <= path.length <= 100
• 1 <= value <= 109
• Each path is valid and consists of lowercase English letters and '/'.
• At most 104 calls in total will be made to createPath and get.

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class FileSystem:

    def __init__(self):
        self.root = {}

    def createPath(self, path: str, value: int) -> bool:
        cur = self.root
        folders = [i for i in path.split('/') if i]
        for i, p in enumerate(folders):
            if i == len(folders) - 1:
                if p in cur:
                    # path already exists
                    return False
                cur[p] = {'#': value}
                return True
            if p not in cur:
                # parent path doesn't exist
                return False
            cur = cur[p]

    def get(self, path: str) -> int:
        cur = self.root
        for p in [i for i in path.split('/') if i]:
            if p not in cur:
                return -1
            cur = cur[p]
        return cur['#']


# Your FileSystem object will be instantiated and called as such:
# obj = FileSystem()
# param_1 = obj.createPath(path,value)
# param_2 = obj.get(path)