LeetCode/简化路径

简化unix文件路径

1. 分割提取+栈

class Solution {
public:
    string simplifyPath(string path) {
        vector<string> names = split(path, '/');//消除/并得到待处理的多段文件名
        vector<string> stack;//这里需要使用栈来判断..的回跳
        for (string& name: names) {
            if (name == ".."){
                if(!stack.empty()) stack.pop_back();//回跳到上一级目录
            }
            else if (!name.empty() && name != ".") //不处理空字符串和单点
                stack.push_back(name);//当前目录入栈
        }
        string ans;
        if (stack.empty())  return "/";//没有访问子目录
        for (string& name: stack) //拼接剩余的目录
                ans += "/" + name;
        return ans;
    }
    vector<string> split (string& s, char delim) {//根据字符划分字符串
        vector<string> ans;
        string cur;
        for (char ch: s) {
            if (ch == delim) {//碰到了分隔符
                ans.push_back(cur);
                cur.clear();
            }
            else cur += ch;
        }
        ans.push_back(cur);
        return ans;
    };
};