LeetCode88 Merge two sort array

description

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.

public class Solution {
public void merge(int[] nums1, int m, int[] nums2, int n) {
if (nums2 == null || nums2.length == 0) {
return;
}
int[] arr = new int[m + n];
int i = 0, j = 0, count = 0;
while (i < m && j < n) {
if (nums1[i] < nums2[j]) {
arr[count++] = nums1[i++];
} else {
arr[count++] = nums2[j++];
}
}
while(i < m) {
arr[count++] = nums1[i++];
}
while(j < n) {
arr[count++] = nums2[j++];
}
System.arraycopy(arr, 0, nums1, 0, n + m);
}
}

updata

class Solution {
/**
* @param A: sorted integer array A which has m elements,
*           but size of A is m+n
* @param B: sorted integer array B which has n elements
* @return: void
*/
public void mergeSortedArray(int[] A, int m, int[] B, int n) {
// write your code here
if (B == null || B.length == 0) {
return;
}
int i = m - 1, j = n - 1, count = m + n - 1;
while (i >= 0 && j >= 0) {
if (A[i] > B[j]) {
A[count--] = A[i--];
} else {
A[count--] = B[j--];
}
}
while (i >= 0) {
A[count--] = A[i--];
}
while (j >= 0) {
A[count--] = B[j--];
}
}
}