solve encode and decode string

Author: sora0319

encode-and-decode-strings/sora0319.java

@@ -0,0 +1,33 @@
+public class Solution {
+    /*
+     * @param strs: a list of strings
+     * @return: encodes a list of strings to a single string.
+     */
+    public String encode(List<String> strs) {
+        StringBuilder sb = new StringBuilder();
+        for (String s : strs) {
+            sb.append(s.length()).append('#').append(s);
+        }
+        return sb.toString();
+    }
+
+    /*
+     * @param str: A single encoded string
+     * @return: decodes the single string to a list of strings
+     */
+    public List<String> decode(String str) {
+        List<String> result = new ArrayList<>();
+        int i = 0;
+        while (i < str.length()) {
+            int j = i;
+            while (str.charAt(j) != '#') {
+                j++;
+            }
+            int length = Integer.parseInt(str.substring(i, j));
+            j++;
+            result.add(str.substring(j, j + length));
+            i = j + length;
+        }
+        return result;
+    }
+}