LeetCode-Easy刷题(18) 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.

将两个排好序的数组合并成一个数组.

//三个指针 从后往前(没新数组)
public void merge(int[] nums1, int m, int[] nums2, int n) {
if(nums1 ==null || nums2 == null){
return;
}
//三个指针
int len = m + n -1;
int one = m -1;
int two = n -1;
while(one>=0&&two>=0){
if(nums1[one]>nums2[two]){
nums1[len] = nums1[one];
one--;
len--;
}else{
nums1[len] = nums2[two];
two--;
len--;
}
}
while(two>=0){
nums1[len] = nums2[two];
len--;
two--;
}
}