88. 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.

Array类题目。

这道题的关键是把两个sorted arrays合并为一个，并且保存在其中一个array中。 因此我们可以从尾部开始处理。 如果nums2还有剩余，则把它依次填满在num1的头部。如果nums1有剩余，则不用操作。

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