LeetCode(88): Merge Sorted Array

Merge Sorted Array: 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.

题意：合并两个有序数组，将nums2的元素合并到nums1中，并且假设nums1数组空间是足够的。其中注意函数的参数，m和n，它们是指要合并的每个数组元素的个数，其分别小于等于各自数组长度。

思路：按照归并排序的思路，因为归并排序中给定的是一个数组的两个区间，所以通常情况下会借助O(n)大小的辅助空间。

代码：

public void merge(int[] nums1, int m, int[] nums2, int n) {
         int pos1=0,pos2=0;
         int all_count = 0;
         int[] temp = new int[m];
         System.arraycopy(nums1,0,temp,0,m);
     
         while(pos1<m&&pos2<n){
             if(temp[pos1]<nums2[pos2]){
                 nums1[all_count] = temp[pos1];
                 pos1++;
                 all_count++;
             }else{
                 nums1[all_count] = nums2[pos2];
                 pos2++;
                 all_count++;
             }
         }
         while(pos1<m){
             nums1[all_count] = temp[pos1];
             pos1++;
            all_count++;
         }
         while(pos2<n){
             nums1[all_count] = nums2[pos2];
             pos2++;
             all_count++;
         }
    }