Problem
You are given two integer arrays nums1 and nums2, sorted in non-decreasing order, and two integers m and n, representing the number of elements in nums1 and nums2 respectively.
Merge nums1 and nums2 into a single array sorted in non-decreasing order.
The final sorted array should not be returned by the function, but instead be stored inside the array nums1. To accommodate this, nums1 has a length of m + n, where the first m elements denote the elements that should be merged, and the last n elements are set to 0 and should be ignored. nums2 has a length of n.
Example 1:
Input: nums1 = [1,2,3,0,0,0], m = 3, nums2 = [2,5,6], n = 3 Output: [1,2,2,3,5,6] Explanation: The arrays we are merging are [1,2,3] and [2,5,6]. The result of the merge is [1,2,2,3,5,6] with the underlined elements coming from nums1.
Example 2:
Input: nums1 = [1], m = 1, nums2 = [], n = 0 Output: [1] Explanation: The arrays we are merging are [1] and []. The result of the merge is [1].
Example 3:
Input: nums1 = [0], m = 0, nums2 = [1], n = 1 Output: [1] Explanation: The arrays we are merging are [] and [1]. The result of the merge is [1]. Note that because m = 0, there are no elements in nums1. The 0 is only there to ensure the merge result can fit in nums1.
Constraints:
nums1.length == m + nnums2.length == n0 <= m, n <= 2001 <= m + n <= 200-109 <= nums1[i], nums2[j] <= 109
Approach
EN
In the beginning, I was thinking to create a new array that has both nums1 array and nums2 array. But soon, I realised I can only return nums1 array in this case. Although, the length of array1 is m+n, the valid value(length) is going to be m and nums2 array length is always going to be n. So I decided to use splice and the startpoint is going to be m+i and the maximum number of i is going to be n-1. After merging arrays, the merged array has to be sorted and negative numbers must be also considered.
- In the for loop, nums2 array is merging nums1 array using
splice. - Since the range of elements of nums1, nums2 includes negative numbers, the sort method needs to include conditional statements
if.
KR
처음에는 새로운 배열을 생성해 nums1과 nums2를 넣어 새로운 배열 = nums1을 하려고 했었다. (무참히 실패)
merge가 중요한 포인트구나 깨닫고 splice를 이용해 푸는 방법을 고안했다.
다만, nums1의 길이가 m+n일지라도 유효한 원소만의 길이는 m이므로 m 다음의 숫자부터 nums2의 원소를 넣어주면 된다. 그러므로 splice 시작포인트는 m+i, 그리고 i가 될 수 있는 최대의 숫자는 n-1일 것이다.
그렇게 머지가 완료 되면 오름차순 정렬을 해주면 되는데, 음수 및 10이상의 양수가 포함되어 있으므로 if 조건문을 사용하여 각 상황에 맞게 리턴값을 다르게 줘 오름차순 정렬했다.
code
/**
* @param {number[]} nums1
* @param {number} m
* @param {number[]} nums2
* @param {number} n
* @return {void} Do not return anything, modify nums1 in-place instead.
*/
var merge = function(nums1, m, nums2, n) {
for(let i=0; i<n; i++){
nums1.splice(m + i, 1, nums2[i]);
}
nums1.sort((a, b) => {
if(a > b) return 1;
if(a < b) return -1;
if(a === b) return 0;
});
};