[LeetCode]71 Simplify Path（模拟）

题目链接：https://leetcode.com/problems/simplify-path/?tab=Description

题意：化简一个绝对路径。

class Solution {
public:
    string simplifyPath(string path) {
        string s;
        int begin = 0, len = 0;
        for(int i = 1; i <= path.length(); i++){
            if(!begin && path[i] != '/') {
                begin = i;
            }
            else if(begin && (path[i] == '/' || i == path.length())) {
                len = i - begin;
            }
            if(len) {
                string ns = path.substr(begin, len);
                begin = len = 0;
                if(!ns.compare(".")) {
                    continue;
                } 
                else if(!ns.compare("..")) {
                    int j(s.length() - 1);
                    while(s[j] != '/') j--;
                    s = s.substr(0, j);
                }
                else s += '/' + ns;
            }
        }
        return s.length() ? s : "/";
    }
};