leetcode [71] Simplify Path
作者:互联网
Given an absolute path for a file (Unix-style), simplify it. Or in other words, convert it to the canonical path.
In a UNIX-style file system, a period . refers to the current directory.Furthermore, a double period .. moves the directory up a level. For more information, see: Absolute path vs relative path in Linux/Unix
Note that the returned canonical path must always begin with a slash /, and there must be only a single slash / between two directory names. The last directory name (if it exists) must not end with a trailing /. Also, the canonical path must be the shortest string representing the absolute path.
Example 1:
Input: "/home/"
Output: "/home"
Explanation: Note that there is no trailing slash after the last directory name.
Example 2:
Input: "/../"
Output: "/"
Explanation: Going one level up from the root directory is a no-op, as the root level is the highest level you can go.
Example 3:
Input: "/home//foo/"
Output: "/home/foo"
Explanation: In the canonical path, multiple consecutive slashes are replaced by a single one.
Example 4:
Input: "/a/./b/../../c/"
Output: "/c"
Example 5:
Input: "/a/../../b/../c//.//"
Output: "/c"
Example 6:
Input: "/a//b////c/d//././/.."
Output: "/a/b/c"
题目大意:
找出简化过后的路径,.表示当前目录(可以忽略不计),..表示上一级目录,目录最后不能带/。
解法:
使用"/"作为划分符号,将path划分得到字符串数组(忽略'.'和空字符串),如果字符串数组中有"..",则将上一个字符串元素删除,最后将字符串使用"/"连接
C++:
class Solution { public: vector<string> split(string path){ int i=0,j=0; vector<string>tmp; while(i<path.size()&&path[i]=='/') i++; j=i; for(;j<path.size();j++){ if(path[j]=='/'){ if(j>i){ tmp.push_back(path.substr(i,j-i)); while(path[j]=='/') j++; i=j; } } } if(path[path.size()-1]!='/'){ int index=path.size()-1; for(;index>=0;index--) if(path[index]=='/') break; tmp.push_back(path.substr(index+1,path.size()-index)); } return tmp; } string simplifyPath(string path) { vector<string>strs; vector<string>p=split(path); for(string str:p){ if(str==".."){ if(!strs.empty()) strs.erase(strs.end()); }else if(str=="."){ continue; }else{ strs.push_back(str); } } string res="/"; for(string s:strs){ res=res+s+"/"; } if(res.size()>1) res=res.substr(0,res.size()-1); return res; } };
太菜了,c++这个split函数实现了半天,还是python和java好,有自带的split函数。
Python:class Solution(object): def simplifyPath(self, path): """ :type path: str :rtype: str """ places=[p for p in path.split("/") if p!="." and p!=""] stack=[] for p in places: if p=="..": if len(stack)>0: stack.pop() else: stack.append(p) return "/"+"/".join(stack)
标签:index,string,..,res,Example,Simplify,71,path,leetcode 来源: https://www.cnblogs.com/xiaobaituyun/p/10627946.html