Rotate Array

rwang23 · rwang23 · commit 72ff652e3bc9 · 2016-03-07T18:36:55.000-05:00
diff --git a/Array/Rotate-Array.md b/Array/Rotate-Array.md
@@ -0,0 +1,43 @@
+##Rotate Array
+
+	Total Accepted: 64166 Total Submissions: 311000 Difficulty: Easy
+	Rotate an array of n elements to the right by k steps.
+
+	For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4].
+
+	Note:
+	Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.
+
+####思路
+- 多次翻转
+- 注意问清面试官题意,自己在这个题意理解上错了好几次,这个rotate的意思就相当于在执行>>操作
+
+```java
+public class Solution {
+    public void rotate(int[] nums, int k) {
+        int n = nums.length;
+        if (k == 0) {
+            return;
+        }
+        if (k >= n) {
+            k = k % n;
+        }
+
+        k = n - k;
+
+        reverse(nums, 0, k - 1);
+        reverse(nums, k , n - 1);
+        reverse(nums, 0, n - 1);
+    }
+
+    public void reverse(int[] nums, int start, int end) {
+        if (start >= end) return;
+
+        for (int i = start, j = end; i < j; i++, j--) {
+            int temp = nums[i];
+            nums[i] = nums[j];
+            nums[j] = temp;
+        }
+    }
+}
+```
diff --git a/Java/notes.md b/Java/notes.md
@@ -38,7 +38,7 @@ Compares its two arguments for order. Returns a negative integer, zero, or a pos
 - Different Ways to Add Parentheses
 
 ###Leetcode一轮虽然做对,但是花时有点长或者需要注意再重做的题
-- Remove Duplicates from Sorted Array
+- Remove Duplicates from Sorted Array I and II
 
 ###难题
 
diff --git a/SUMMARY.md b/SUMMARY.md
@@ -150,6 +150,7 @@ This is the summary of my experience in LintCode.
 
 
 * [Array](Array/README.md)
+	* [Rotate Array](Array/Rotate-Array.md)
 	* [Shortest Word Distance](Array/Shortest-Word-Distance.md)
 	* [Shortest Word Distance II](Array/Shortest-Word-Distance-II.md)
 	* [Shortest Word Distance III](Array/Shortest-Word-Distance-III.md)
