solve problem Simplify Path

Author: P-ppc

README.md

@@ -312,6 +312,7 @@ All solutions will be accepted!
 |299|[Bulls And Cows](https://leetcode-cn.com/problems/bulls-and-cows/description/)|[java/py/js](./algorithms/BullsAndCows)|Medium|
 |394|[Decode String](https://leetcode-cn.com/problems/decode-string/description/)|[java/py/js](./algorithms/DecodeString)|Medium|
 |938|[Range Sum Of Bst](https://leetcode-cn.com/problems/range-sum-of-bst/description/)|[java/py/js](./algorithms/RangeSumOfBst)|Medium|
+|71|[Simplify Path](https://leetcode-cn.com/problems/simplify-path/description/)|[java/py/js](./algorithms/SimplifyPath)|Medium|
 
 # Database
 |#|Title|Solution|Difficulty|

algorithms/SimplifyPath/README.md

@@ -0,0 +1,2 @@
+# Simplify Path
+We can solve this problem by stack

algorithms/SimplifyPath/Solution.java

@@ -0,0 +1,23 @@
+class Solution {
+    public String simplifyPath(String path) {
+        LinkedList<String> stack = new LinkedList<String>();
+        StringBuilder sb = new StringBuilder();
+        
+        for (String part : path.split("/")) {
+            if (!part.equals("") && !part.equals(".") && !part.equals(".."))
+                stack.push(part);
+            else if (part.equals("..") && stack.size() > 0)
+                stack.pop();
+        }
+        
+        if (stack.size() == 0)
+            sb.append("/");
+        
+        while (stack.size() > 0) {
+            sb.append("/");
+            sb.append(stack.pollLast());
+        }
+        
+        return sb.toString();
+    }
+}

algorithms/SimplifyPath/solution.js

@@ -0,0 +1,16 @@
+/**
+ * @param {string} path
+ * @return {string}
+ */
+var simplifyPath = function(path) {
+    let stack = []
+    
+    path.split('/').forEach(part => {
+        if (part != '' && part != '.' && part != '..')
+            stack.push(part)
+        else if (part == '..' && stack.length > 0)
+            stack.pop()
+    })
+    
+    return '/' + stack.join('/')
+};

algorithms/SimplifyPath/solution.py

@@ -0,0 +1,14 @@
+class Solution(object):
+    def simplifyPath(self, path):
+        """
+        :type path: str
+        :rtype: str
+        """
+        stack = []
+        for part in path.split('/'):
+            if part != '' and part != '.' and part != '..':
+                stack.append(part)
+            elif part == '..' and len(stack) > 0:
+                stack.pop()
+        
+        return '/' + '/'.join(stack)