longest_abs_path.py

# def lengthLongestPath(input):
    # maxlen = 0
    # pathlen = {0: 0}
    # for line in input.splitlines():
        # print("---------------")
        # print("line:", line)
        # name = line.strip('\t')
        # print("name:", name)
        # depth = len(line) - len(name)
        # print("depth:", depth)
        # if '.' in name:
            # maxlen = max(maxlen, pathlen[depth] + len(name))
        # else:
            # pathlen[depth + 1] = pathlen[depth] + len(name) + 1
        # print("maxlen:", maxlen)
    # return maxlen

# def lengthLongestPath(input):
    # paths = input.split("\n")
    # level = [0] * 10
    # maxLength = 0
    # for path in paths:
        # print("-------------")
        # levelIdx = path.rfind("\t")
        # print("Path: ", path)
        # print("path.rfind(\\t)", path.rfind("\t"))
        # print("levelIdx: ", levelIdx)
        # print("level: ", level)
        # level[levelIdx + 1] = level[levelIdx] + len(path) - levelIdx + 1
        # print("level: ", level)
        # if "." in path:
            # maxLength = max(maxLength, level[levelIdx+1] - 1)
            # print("maxlen: ", maxLength)
    # return maxLength

def length_longest_path(input):
    """
    :type input: str
    :rtype: int
    """
    currlen, maxlen = 0, 0    # running length and max length
    stack = []    # keep track of the name length
    for s in input.split('\n'):
        print("---------")
        print("<path>:", s)
        depth = s.count('\t')    # the depth of current dir or file
        print("depth: ", depth)
        print("stack: ", stack)
        print("curlen: ", currlen)
        while len(stack) > depth:    # go back to the correct depth
            currlen -= stack.pop()
        stack.append(len(s.strip('\t'))+1)   # 1 is the length of '/'
        currlen += stack[-1]    # increase current length
        print("stack: ", stack)
        print("curlen: ", currlen)
        if '.' in s:    # update maxlen only when it is a file
            maxlen = max(maxlen, currlen-1)    # -1 is to minus one '/'
    return maxlen

st= "dir\n\tsubdir1\n\t\tfile1.ext\n\t\tsubsubdirectory1\n\tsubdir2\n\t\tsubsubdir2\n\t\t\tfile2.ext"
st2 = "a\n\tb1\n\t\tf1.txt\n\taaaaa\n\t\tf2.txt"
print("path:", st2)

print("answer:", lengthLongestPath(st2))