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.

Pay attention to comparison change due to backward scaning.

Solution:

public class Solution {
    public void merge(int[] nums1, int m, int[] nums2, int n) {
        int s1 = m - 1;
        int s2 = n - 1;
        int s = m + n - 1;
        while(s>=0){
            if(s1==-1) while(s>=0) nums1[s--] = nums2[s2--];
            else if(s2==-1) while(s>=0) nums1[s--] = nums1[s1--];
            /* pay attention to comparison change due to backward scaning */
            else nums1[s--] = nums1[s1]>nums2[s2] ? nums1[s1--] : nums2[s2--];
        }
    }
}