LC 88 Merge Sorted Array

Implementation

// 88. Merge Sorted Array

// 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 + n
// nums2.length == n
// 0 <= m, n <= 200
// 1 <= m + n <= 200
// -109 <= nums1[i], nums2[j] <= 109

var merge = (nums1, m, nums2, n) => {
    let i = m - 1;
    let j = n - 1;
    let k = m+n-1;
    while (i >= 0 && j >= 0) {
        if (nums1[i] < nums2[j]) {
            nums1[k--] = nums2[j--];
        } else {
            nums1[k--] = nums1[i--];
        }
    }
    while(j>=0){
        nums1[k--]=nums2[j--];
    }
    return nums1;
};
console.log(merge([1, 2, 3, 0, 0, 0], 3, [2, 5, 6], 3));
console.log(merge([1], 1, [], 0));
console.log(merge([0], 0, [1], 1));

Tests

// Test stub for 03.88.MergeSortedArray

describe('03.88.MergeSortedArray', () => {
  it('should have a test stub', () => {
    expect(true).toBe(true);
  });
});