71. Simplify Path
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".
java的split函数，只要separator的前“或者”后没有“别的”字符串就会返回一个空。
linux系统当中，多余两个的点会被当作普通路径处理。
public class Solution {
public String simplifyPath(String path) {
if (path.length() == 0) {
return "";
}
String[] strs = path.split("/");
StringBuilder result = new StringBuilder();
LinkedList<String> stack = new LinkedList<String>();
for (String string : strs) {
switch (string) {
case "": stack.offer("/"); break;
case ".": break;
case "..": while (!stack.isEmpty() && stack.removeLast().equals("/")); break;
default: stack.offer(string);
}
}
if (path.charAt(0) == '/') {
result.append('/');
}
while (!stack.isEmpty()) {
String string = stack.removeFirst();
if (!string.equals("/")) {
result.append(string);
result.append('/');
}
}
int ll = result.length();
if (ll > 1 && result.charAt(ll - 1) == '/') {
result.deleteCharAt(ll - 1);
}
return result.toString();
}
}