From 65da0147fee323b9acf951fe7dc6099798a486e5 Mon Sep 17 00:00:00 2001
From: ShusenTang <tangshusen@pku.edu.cn>
Date: Mon, 23 Dec 2019 16:31:51 +0800
Subject: [PATCH] Create 388. Longest Absolute File Path.md

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 solutions/388. Longest Absolute File Path.md | 43 ++++++++++++++++++++
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 create mode 100644 solutions/388. Longest Absolute File Path.md

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+# [388. Longest Absolute File Path](https://leetcode.com/problems/longest-absolute-file-path/)
+# 思路
+这道题给了我们一个字符串，里面包含 \n 和 \t 这种表示回车和空格的特殊字符，让我们找到某一个最长的绝对文件路径。
+
+我们可以从前往后遍历输入字符串，用一个数组记录每一层文件夹的绝对路径长度，用一个tag来标记是否是文件（一旦遇到了'.'就是文件），
+用变量depth记录当前文件（夹）的层次（有多少'\t'就有多深）。
+
+
+# C++
+``` C++
+class Solution {
+public:
+    int lengthLongestPath(string input) {
+        int l = 0, r = 0, depth = 0, res = 0, input_size = input.size();
+        vector<int>dir_lens;
+        bool file_tag = false;
+        while(r <= input_size){
+            if(r == input_size || input[r] == '\n'){ //遇到换行符, 处理r之前的
+                if(!file_tag){ // 是个dir
+                    // 加1是因为 xxx/xxx/ 里面的斜杠
+                    int tmp = 1 + r - l + (depth == 0 ? 0: dir_lens[depth - 1]);
+                    if(dir_lens.size() == depth) dir_lens.push_back(tmp);
+                    else dir_lens[depth] = tmp;
+                }
+                else res = max(res, r - l + (depth == 0 ? 0: dir_lens[depth - 1]));
+                
+                depth = 0; file_tag = false; // 初始化
+                while(r + 1 < input_size && input[r+1] == '\t') {
+                    r += 1;
+                    depth += 1; // 有多少'\t'就有多深
+                }
+                
+                l = r + 1;
+            }
+            else if(r < input_size && input[r] == '.') file_tag = true;
+
+            r++;
+        }
+        
+        return res;
+    }
+};
+```