88. Merge Sorted Array

Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.

Note:

• The number of elements initialized in nums1 and nums2 are m and n respectively.
• You may assume that nums1 has enough space (size that is greater or equal to m + n) to hold additional elements from nums2.

Example:

Input:
nums1 = [1,2,3,0,0,0], m = 3
nums2 = [2,5,6],       n = 3

Output: [1,2,2,3,5,6]

class Solution {
    public void merge(int[] nums1, int m, int[] nums2, int n) {
        int tail1 = m - 1;
        int tail2 = n - 1;
        int finished = m + n - 1;
        while(tail1 >=0 && tail2 >= 0){
            nums1[finished--] = nums1[tail1] > nums2[tail2] ? nums1[tail1--] : nums2[tail2--];
        }
        while(tail2 >= 0){
            nums1[finished--] = nums2[tail2--];
        }
    }
}

 

思想：比较末尾数，大的也存放到末尾

如果nums1还有余（tail1>=0)没有影响,如m=3,n=2

如果nums2还有鱼（tail2>=0)，继续往后插入就可以,如m=2,n=3