[Leetcode 60] 71 Simplify Path

Problem:

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"

.

Analysis:

Simulation problem, with the help of a vector keeping record of the current path and either push a new path node or pop the older path node or do nothing to maintain the final path.

Need to pay special attention to those corner cases.

Code:

class Solution {
public:
string simplifyPath(string path) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
vector<string> stack;
stack.push_back("/");

int p1 = 0, p2 = 0;
while (true) {
while (path[p1] == '/' && p1<path.size())
p1++;

p2 = p1+1;
while (path[p2] != '/' && p2<path.size())
p2++;

if (p2 > path.size()) break;

string tmp = path.substr(p1, p2-p1);
if (tmp == "..") {
if (stack.size() != 1)
stack.pop_back();
}
else if (tmp == ".")
;//do nothing
else
stack.push_back(tmp);

p1 = p2;
}

if (stack.size() == 1)
return "/";
else {
string tmp;
for (int i=1; i<stack.size(); i++)
tmp += "/" + stack[i];
return tmp;
}
}
};

View Code