leetcode:Longest Absolute File Path

Suppose we abstract our file system by a string in the following manner:

The string “dir\n\tsubdir1\n\tsubdir2\n\t\tfile.ext” represents:

dir
subdir1
subdir2
file.ext
The directory dir contains an empty sub-directory subdir1 and a sub-directory subdir2 containing a file file.ext.

The string “dir\n\tsubdir1\n\t\tfile1.ext\n\t\tsubsubdir1\n\tsubdir2\n\t\tsubsubdir2\n\t\t\tfile2.ext” represents:

dir
subdir1
file1.ext
subsubdir1
subdir2
subsubdir2
file2.ext
The directory dir contains two sub-directories subdir1 and subdir2. subdir1 contains a file file1.ext and an empty second-level sub-directory subsubdir1. subdir2 contains a second-level sub-directory subsubdir2 containing a file file2.ext.

We are interested in finding the longest (number of characters) absolute path to a file within our file system. For example, in the second example above, the longest absolute path is “dir/subdir2/subsubdir2/file2.ext”, and its length is 32 (not including the double quotes).

Given a string representing the file system in the above format, return the length of the longest absolute path to file in the abstracted file system. If there is no file in the system, return 0.

要求求出最长的文件路径的长度值
模拟题目，按照题目模拟即可

public class Solution {    public static void main(String[] args) {        // TODO Auto-generated method stub        Solution s = new Solution();        int len = 0;//      len = s.lengthLongestPath("dir\n\tsubdir1\n\t\tfile1.ext\n\t\t"//              + "subsubdir1\n\tsubdir2\n\t\tsubsubdir2\n\t\t\tfile2.ext");//      len = s.lengthLongestPath("dir\n\tsubdir1\n\tsubdir2\n\t\tfile.ext");;        len = s.lengthLongestPath("dir\n\tsubdir1\n\tsubdir2\n\t\tfile.ext");        System.out.println(len);//      System.out.println("dir\n\tsubdir1\n\t\tfile1.ext\n\t\t"//              + "subsubdir1\n\tsubdir2\n\t\tsubsubdir2\n\t\t\tfile2.ext");//      System.out.println("dir\n\tsubdir1\n\t\tfile1.ext\n\t\tsubsubdir1\n\tsubdir2\n\t\tsubsubdir2\n\t\t\tfile2.ext".length());    }    public int lengthLongestPath(String input) {        String ans = "";        char[] chs = input.toCharArray();        String[] dir = new String[input.length()];        int dirIndex = 0;        int pre = 0;        for(int i = 0; i < chs.length; ++i){            if(chs[i] == '\n' || i == chs.length - 1){                String temp = new String(chs, pre, i == chs.length - 1 ? i - pre + 1 : i - pre);                 dir[dirIndex] = temp;                pre = i + 1;//              System.out.println(temp);                dir[dirIndex] = temp;                if(temp.indexOf(".") == -1){                    dirIndex = 0;                    continue;                }                String d = "";                for(int j = 0; j < dirIndex; ++j){                    d += dir[j]+"/";                }                d += temp;//              System.out.println(d);                if(d.length() > ans.length()){                    ans = d;                }                dirIndex = 0;            }            if(chs[i] == '\t'){                dirIndex++;                pre = i + 1;            }        }        return ans.length();    }}