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.

Tips:

从后往前插入即可。

Code：

public class Solution {
    public void merge(int[] nums1, int m, int[] nums2, int n) {
        int index = m + n - 1;
        int i = m - 1;
        int j = n - 1;
        while (i >= 0 && j >= 0) {
            if (nums1[i] > nums2[j]) {
                nums1[index] = nums1[i];
                index--;
                i--;
            } else {
                nums1[index] = nums2[j];
                index--;
                j--;
            }
        }
        while (i >= 0) {
            nums1[index] = nums1[i];
            index--;
            i--;
        }
        while (j >= 0) {
            nums1[index] = nums2[j];
            index--;
            j--;
        }
    }
}