leetcode 71 Simplify Path

leetcode 71 Simplify Path

原题链接：https://leetcode.com/problems/simplify-path/

Description

Given an absolute path for a file (Unix-style), simplify it.

For example,

path = “/home/”, => “/home”

path = “/a/./b/../../c/”, => “/c”

Solution

简化linux文件路径,”.”代表当前目录,”..”代表上级目录

大体做法:先把path按’/’符分割保存起来(由于c++ string没有split函数,自己写一个吧)

再把切割后的字符串扫一遍即可。

具体如下

class Solution {
public:
string simplifyPath(string path) {
string ans;
if(path.empty()) return ans;
auto split = [=](char sep = '/')->vector<string> {
string temp;
vector<string> res;
size_t start = 0, end = 0;
while((end = path.find(sep, start)) != string::npos) {
temp = path.substr(start, end - start);
if(temp != "") res.emplace_back(temp);
start = end + 1;
}
temp = path.substr(start);
if(temp != "") res.emplace_back(temp);
return res;
};
vector<string> res = split();
vector<string> stk;
for(auto &r: res) {
if(r ==".") continue;
else if(r == "..") {
if(!stk.empty()) stk.pop_back();
} else {
stk.push_back(r);
}
}
if(stk.empty()) {
ans.push_back('/');
} else {
for(auto &r: stk) {
ans.push_back('/');
ans += r;
}
}
return ans;
}
};