Add Stacks folder and 71_Simplify_Path.java

Author: seanprashad

Stacks/71_Simplify_Path.java

@@ -0,0 +1,29 @@
+class Solution {
+    public String simplifyPath(String path) {
+        if (path == null || path.isEmpty()) {
+            return "";
+        }
+
+        Stack<String> st = new Stack<>();
+        StringBuilder sb = new StringBuilder();
+        String[] components = path.split("/");
+
+        for (String s : components) {
+            if (s.isEmpty() || s.equals(".")) {
+                continue;
+            } else if (s.equals("..")) {
+                if (!st.isEmpty()) {
+                    st.pop();
+                }
+            } else {
+                st.push(s);
+            }
+        }
+
+        for (String dir : st) {
+            sb.append("/").append(dir);
+        }
+
+        return sb.length() == 0 ? "/" : sb.toString();
+    }
+}