88. Merge Sorted Array

88. Merge Sorted Array (Easy)

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

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 equal to m + n) to hold additional elements from nums2.

 

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]

Example 2:

Input: nums1 = [1], m = 1, nums2 = [], n = 0
Output: [1]

 

Constraints:

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

Related Topics:
Array, Two Pointers

Similar Questions:

• Merge Two Sorted Lists (Easy)
• Squares of a Sorted Array (Easy)
• Interval List Intersections (Medium)

Solution 1.

// OJ: https://leetcode.com/problems/merge-sorted-array/
// Author: github.com/lzl124631x
// Time: O(M + N)
// Space: O(1)
class Solution {
public:
    void merge(vector<int>& A, int m, vector<int>& B, int n) {
        for (int i = m - 1, j = n - 1, k = m + n - 1; k >= 0;) {
            if (j < 0 || (i >= 0 && A[i] > B[j])) A[k--] = A[i--];
            else A[k--] = B[j--];
        }
    }
};