Merge pull request #221 from gpfpter/剑指-Offer-58---II.-左旋转字符串-Java代码提交-1

剑指 Offer 58 - II. 左旋转字符串 Java代码提交

problems/剑指Offer58-II.左旋转字符串.md

@@ -96,10 +96,27 @@ public:
 
 ## 其他语言版本
 
-
 Java：
-
-
+```java
+class Solution {
+    public String reverseLeftWords(String s, int n) {
+        int len=s.length();
+        StringBuilder sb=new StringBuilder(s);
+        reverseString(sb,0,n-1);
+        reverseString(sb,n,len-1);
+        return sb.reverse().toString();
+    }
+     public void reverseString(StringBuilder sb, int start, int end) {
+        while (start < end) {
+            char temp = sb.charAt(start);
+            sb.setCharAt(start, sb.charAt(end));
+            sb.setCharAt(end, temp);
+            start++;
+            end--;
+            }
+        }
+}
+```
 Python：