[Swift]LeetCode71. 简化路径 | Simplify Path

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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".

---

 给定一个文档 (Unix-style) 的完全路径，请进行路径简化。

例如，
path = "/home/", => "/home"
path = "/a/./b/../../c/", => "/c"

边界情况:

• 你是否考虑了 路径 = "/../" 的情况？
  在这种情况下，你需返回 "/" 。
• 此外，路径中也可能包含多个斜杠 '/' ，如 "/home//foo/" 。
  在这种情况下，你可忽略多余的斜杠，返回 "/home/foo" 。

---

 28ms

class Solution {
    func simplifyPath(_ path: String) -> String {
        let paths = path.components(separatedBy:"/")
        var stack = [String]()
        for str in paths {
            if str == "." || str == ""{
                
            } else if str == ".." {
                stack.popLast()
            } else {
                stack.append(str)
            }
        }
        
        var result = "/"
        for i in 0..<stack.count {
            let str = stack[i]
            if i == stack.count - 1 {
                result += str
            } else {
                result += str + "/"
            }
        }
        
        return result
    }
}

---

32ms

class Solution {
    func simplifyPath(_ path: String) -> String {
        let cmpt = path.components(separatedBy: "/")
        var ret: [String] = []
        for item in cmpt {
            if item == ".." {
                if ret.count > 0 {
                    ret.removeLast()
                }
            } else if item == "." {
                continue
            } else if item == "" {
                continue
            } else {
                ret.append(item)
            }
        }
        return "/" + ret.joined(separator: "/")
    }
    
}

---

32ms

class Solution {
    func simplifyPath(_ path: String) -> String {
        let arr = path.split{ $0=="/" }.map(String.init)
        var stack = [String]()
        for s in arr {
            if s == "" || s == "." { continue }
            if s == ".." { _ = stack.popLast(); continue; }
            stack.append(s)
        }
        return stack.isEmpty ? "/" : "/" + stack.joined(separator:"/")
    }
}

---

40ms

class Solution {
    func simplifyPath(_ path: String) -> String {
        var components = path.split(separator: "/")
        var stack = [String.SubSequence]()
        
        for component in components {
            if component == "." {
                continue
            } else if component == ".." {
                stack.popLast()
            } else {
                stack.append(component)
            }
        }
        
        var output = "/"
        
        for (index, pathComponent) in stack.enumerated() {
            if index == stack.count - 1 {
                output += pathComponent
            } else {
                output += pathComponent + "/"
            }
        }
        
        return output
    }
}

---

48ms

class Solution {
    func simplifyPath(_ path: String) -> String {
        var myPath = [String]()
        let presentedPath = path.components(separatedBy: "/")
        
        for path in presentedPath {
            if path.count <= 0 {continue}
            if path == "." {
                continue
            } else if path == ".." {
                if myPath.count > 0 {myPath.removeLast()}
            } else {
                myPath.append(path)
            }
        }
        
        var absolutePath = ""
        
        for path in myPath {
            absolutePath = absolutePath.count == 0 ? "/\(path)": absolutePath + "/\(path)"
        }
        return absolutePath.count > 0 ? absolutePath : "/" 
    }
}