题目：
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.
解决方案一： Runtime：1ms
public class Solution { public void merge(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 while(j>=0&&nums1[i]<=nums2[j]){ nums1[k--]=nums2[j--]; } } while(j>=0){ nums1[k--]=nums2[j--]; } } }仔细分析代码，else中的循环是不必要的，可以去掉得到：
解决方案二：
public class Solution { public void merge(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--]; } } }参考：
【1】https://leetcode.com/
