Leetcode [609. Find Duplicate File in System]

Problem：609. Find Duplicate File in System

Question

Given a list of directory info including directory path, and all the files with contents in this directory, you need to find out all the groups of duplicate files in the file system in terms of their paths.

A group of duplicate files consists of at least two files that have exactly the same content.

A single directory info string in the input list has the following format:

"root/d1/d2/.../dm f1.txt(f1_content) f2.txt(f2_content) ... fn.txt(fn_content)"

It means there are n files ( f1.txt, f2.txt … fn.txt with content f1_content, f2_content … fn_content, respectively ) in directory root/d1/d2/…/dm. Note that n >= 1 and m >= 0. If m = 0, it means the directory is just the root directory.

The output is a list of group of duplicate file paths. For each group, it contains all the file paths of the files that have the same content. A file path is a string that has the following format:

"directory_path/file_name.txt"

Example 1:
Input:

["root/a 1.txt(abcd) 2.txt(efgh)", "root/c 3.txt(abcd)", "root/c/d 4.txt(efgh)", "root 4.txt(efgh)"]

Output:

[["root/a/2.txt","root/c/d/4.txt","root/4.txt"],["root/a/1.txt","root/c/3.txt"]]

Note:

1. No order is required for the final output.
2. You may assume the directory name, file name and file content only has letters and digits, and the length of file content is in the range of [1,50].
3. The number of files given is in the range of [1,20000].
4. You may assume no files or directories share the same name in the same directory.
5. You may assume each given directory info represents a unique directory. Directory path and file info are separated by a single blank space.

思路

1. 遍历整个vector，将每个vector中的string split，分离出根目录(root/a…)，txt文件名；
2. 对每个txt后缀的文件，拿出文件内容，同时按照文件内容做以下操作。（用一个vector把这些文件归类）
   
   • 如果已经存在一个vector将这些文件归类，那就在把该文件插入vector
   • 如果没有，新构造一个vector，然后把当前文件加入进去。
3. 如果将这个新构造的vector加入result中
4. 最后，从头到尾遍历result，把result里面长度大于1的文件序列拿出来。
5. 完

解题代码

#include<iostream>#include<string>#include<vector>#include<map>using namespace std;class Solution {public:    vector<vector<string>> findDuplicate(vector<string>& paths) {        map<string, int> content;        vector<vector<string>> result;        int count = 0;        for(auto p : paths) {            vector<string> sperate = split(p, " ");            for (int i = 1; i < sperate.size(); i++) {                string c = getContent(sperate[i]);                if (content.find(c) == content.end()) {                    content[c] = count;                    count++;                    std::vector<string> newPath;                    newPath.push_back(sperate[0]+"/"+sperate[i]);                    result.push_back(newPath);                }                else {                    int pos = content.find(c)->second;                    result[pos].push_back(sperate[0] + "/" + sperate[i]);                }            }        }        vector<vector<string>> last;        for(auto seq : result) {            if (seq.size() > 1)                last.push_back(seq);        }        return last;    }    vector<string> split(string &str, string sperator) {        int pos1 = 0;        int pos2 = str.find(sperator);        std::vector<string> result;        while (string::npos != pos2) {            result.push_back(str.substr(pos1, pos2-pos1));            pos1 = pos2 + sperator.size();            pos2 = str.find(sperator, pos1);        }        if (pos1 != str.length())            result.push_back(str.substr(pos1));        return result;    }    string getContent(string &str) {        int start = str.find('(');        int end = str.find(')');        string res = str.substr(start+1, end+start-1);        str = str.substr(0, start);        return res;    }};