[LeetCode] Simplify Path

标签：c++   leetcode   

Simplify Path

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

For example,
path = "/home/", => "/home"
path = "/a/./b/../../c/", => "/c"

click to show corner cases.

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".

解题思路：

化简路径。可以用一个栈来记录。遍历原路径，遇到/，则判断最近一个单词。若为"."则什么也不做。若".."，弹出栈顶元素，否则入栈。

有一个比较巧的办法是，直接在path后面添加一个斜杠，这样就能避免讨论后面有斜杠还是没有斜杠了。

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

[LeetCode] Simplify Path

标签：c++   leetcode   

原文地址：http://blog.csdn.net/kangrydotnet/article/details/47105813