optimize 88

fishercoder1534 · fishercoder1534 · commit 3b186448e3c0 · 2017-05-13T16:56:16.000-07:00
diff --git a/README.md b/README.md
@@ -349,6 +349,7 @@ Your ideas/fixes/algorithms are more than welcome!
 |92|[Reverse Linked List II](https://leetcode.com/problems/reverse-linked-list-ii/)|[Solution](../master/src/main/java/com/stevesun/solutions/_92.java)| O(n)|O(1) | Medium
 |91|[Decode Ways](https://leetcode.com/problems/decode-ways/)|[Solution](../master/src/main/java/com/stevesun/solutions/DecodeWays.java)| O(n)|O(n) | Medium| DP
 |89|[Gray Code](https://leetcode.com/problems/gray-code/)|[Solution](../master/src/main/java/com/stevesun/solutions/GrayCode.java)|O(n) |O(1)|Medium|Bit Manipulation
+|88|[Merge Sorted Array](https://leetcode.com/problems/merge-sorted-array/)|[Solution](../master/src/main/java/com/stevesun/solutions/_88.java)|O(max(m,n)) |O(1)|Easy|
 |86|[Partition List](https://leetcode.com/problems/partition-list/)|[Solution](../master/src/main/java/com/stevesun/solutions/PartitionList.java)|O(?) |O(?)|Medium|
 |85|[Maximal Rectangle](https://leetcode.com/problems/maximal-rectangle/)|[Solution](../master/src/main/java/com/stevesun/solutions/MaximalRectangle.java)|O(m*n) |O(n)|Hard|DP
 |83|[Remove Duplicates from Sorted List](https://leetcode.com/problems/remove-duplicates-from-sorted-list/)|[Solution](../master/src/main/java/com/stevesun/solutions/_83.java)|O(n) |O(1)|Medium| Linked List
diff --git a/src/main/java/com/stevesun/solutions/_88.java b/src/main/java/com/stevesun/solutions/_88.java
@@ -3,11 +3,24 @@
 /**Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.
 
  Note:
- You may assume that nums1 has enough space (size that is greater or equal to m + n) to hold additional elements from nums2. The number of elements initialized in nums1 and nums2 are m and n respectively.*/
+ You may assume that nums1 has enough space (size that is greater or equal to m + n)
+ to hold additional elements from nums2. The number of elements initialized in nums1 and nums2 are m and n respectively.*/
 
-public class MergeSortedArray {
+public class _88 {
 
-    /**I used O(m) extra space to create a temp array, but this could be avoided.*/
+    //credit:https://discuss.leetcode.com/topic/2461/this-is-my-ac-code-may-help-you
+    public static void merge_O1_space(int[] nums1, int m, int[] nums2, int n) {
+        int i = m-1;
+        int j = n-1;
+        int k = m+n-1;
+        while (i >= 0 && j >= 0) {
+            if (nums1[i] > nums2[j]) nums1[k--] = nums1[i--];
+            else nums1[k--] = nums2[j--];
+        }
+        while (j >= 0) nums1[k--] = nums2[j--];
+    }
+
+    /**I used O(m) extra space to create a temp array, but this could be optimized.*/
     public static void merge(int[] nums1, int m, int[] nums2, int n) {
         int[] temp = new int[m];
         for(int i = 0; i < m; i++) temp[i] = nums1[i];
