Simplify Path

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

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

• Time: O(n)
• Space: O(1)

public String simplifyPath(String path) {
    String[] strs = path.split("/");
    Stack<String> stack = new Stack<>();
    for (String str : strs) {
        if (str.length() == 0 || str.equals(".")) {
            continue;
        } else if (str.equals("..")) {
            if (!stack.isEmpty()) stack.pop();
        } else {
            stack.push(str);
        }
    }
    StringBuilder sb = new StringBuilder();
    while (!stack.isEmpty()) {
        sb.insert(0, "/" + stack.pop());
    }
    return sb.length() == 0 ? "/" : sb.toString();
}