88. Merge Sorted Array

The tricky part is we need to start from the end of arrays such that the largest will be allocated in the end.

1:  class Solution {  
2:  public:  
3:    void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {  
4:      int i = m-1;  
5:      int j = n-1;  
6:      int k = m+n-1;  
7:      while (i >= 0 && j >= 0) {  
8:        if (nums1[i] > nums2[j]) {  
9:          nums1[k--] = nums1[i--];  
10:        } else {  
11:          nums1[k--] = nums2[j--];  
12:        }  
13:      }  
14:      while (j >= 0) nums1[k--] = nums2[j--];  
15:    }  
16:  };