MergeSortedArray.cpp

/*
Description:
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.
=====
Constraints:
(1) nums1.length == m + n
(2) nums2.length == n
(3) 0 <= m, n <= 200
(4) 1 <= m + n <= 200
(5) -10^9 <= nums1[i], nums2[j] <= 10^9
=====
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.
*/
#include<iostream> 
#include<vector>
using namespace std;
class Solution {
public:
    void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
        if(n == 0){
            return;
        }
        
        int mIndex = 0;
        int nIndex = 0;
        while(nIndex < n){
            if(nums1[mIndex] > nums2[nIndex] || nums1.size()-mIndex == n-nIndex){
                nums1.insert(nums1.begin() + mIndex, nums2[nIndex]);
                nums1.pop_back();

                mIndex++;
                nIndex++;
            }else{
                mIndex++;
            }
        }
    }
};

int main() { 
    Solution solution;
    std::vector nums1 = {1,2,3,0,0,0};
    int m = 3;
    std::vector nums2 = {2,5,6};
    int n = 3;

    solution.merge(nums1, m, nums2, n);

    for(int num : nums1){
        cout << num << " ";
    }
    cout << endl;
    return 0; 
}