71. Simplify Path (java)

Author: bluesword12350

solution/0071.Simplify Path/Solution.java

@@ -0,0 +1,26 @@
+class Solution {
+    public String simplifyPath(String path) {
+        List<String> dirs = new ArrayList<>();
+        int dirStart = 0, len = path.length();
+        while (dirStart < len) {
+            while (dirStart < len && path.charAt(dirStart) == '/') dirStart++;
+            int dirEnd = dirStart;
+            while (dirEnd < len && path.charAt(dirEnd) != '/') dirEnd++;
+            String dir = path.substring(dirStart, dirEnd);
+            if (!".".equals(dir)) {
+                if ("..".equals(dir)) {
+                    if (! dirs.isEmpty()) dirs.remove(dirs.size() - 1);
+                } else if (dir.length() > 0) {
+                    dirs.add(dir);
+                }
+            }
+            dirStart = ++dirEnd;
+        }
+        StringBuilder sb = new StringBuilder("/");
+        for (int i = 0; i < dirs.size(); i++) {
+            if (i == dirs.size() - 1) sb.append(dirs.get(i));
+            else sb.append(dirs.get(i)).append("/");
+        }
+        return sb.toString();
+    }
+}