Given an absolute path for a file (Unix-style), simplify it.
For example,
path = "/home/"
, => "/home"
path = "/a/./b/../../c/"
, => "/c"
Corner Cases:
- Did you consider the case where path =
"/../"
?
In this case, you should return"/"
. - Another corner case is the path might contain multiple slashes
'/'
together, such as"/home//foo/"
.
In this case, you should ignore redundant slashes and return"/home/foo"
.
题目不难,主要考虑一些特殊情况。
对于path = "/a/./b/../../c/"
, => "/c",模拟一下
先按照'/'对字符串进行分割,得到 [a, . , b, .. , .. , c]
首先进入目录a,注意 '.' 代表当前目录 ,".."代表上一个目录
然后到达'.',还是在当前目录,/a
然后到达'b',这为/a/b
然后到达'..',这是回到父目录,则变为/a
然后到达'..',继续回到父目录,则变为/
然后到达'c',则达到子目录,变为/c
class Solution {
public:
vector<string> split(string& path, char ch){
int index = ;
vector<string> res;
while(index < path.length()){
while(index < path.length() && path[index] == '/') index++;
if(index >= path.length()) break;
int start=index, len = ;
while(index < path.length() && path[index]!='/') {index++;len++;}
res.push_back(path.substr(start,len));
}
return res;
} string simplifyPath(string path) {
vector<string> a = split(path,'/');
vector<string> file;
for(int i = ; i < a.size(); ++ i){
if(a[i] == ".." ){
if(!file.empty()) file.pop_back();
}
else if(a[i]!=".") file.push_back(a[i]);
}
string res="";
if(file.empty()) res ="/";
else{
for(int i = ; i < file.size(); ++ i) res+="/"+file[i];
}
return res;
}
};