[leetcode] 【字符串】71. Simplify Path

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"

.

题意

简化unix风格的绝对路径

题解

有几种情况需要处理   一是多个/只当1个/处理

二是..表示进入父目录

用一个栈结构存储目录路径的每个文件夹，遇到..则出栈

class Solution {
public:
string simplifyPath(string path) {
stack<string> file;
for(int i=0;i<path.size();)
{
while(path[i]=='/'&&i<path.size())
i++;
string temp;
while(path[i]!='/'&&i<path.size())
temp+=path[i++];
if(temp==".."&&!file.empty())
file.pop();
if(temp!="."&&temp!=".."&&temp!="")
file.push(temp);
}
string res;
if(file.empty())
res="/";
while(!file.empty())
{
res=file.top()+res;
res='/'+res;
file.pop();
}
return res;
}
};