MergeSorted.cpp

/*
Link:https://leetcode.com/explore/interview/card/top-interview-questions-easy/96/sorting-and-searching/587/

Merge Sorted Array

Solution
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.
*/

class Solution {
public:
    void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
        
        int i=m-1;
        int j=n-1;
        int idx=m+n-1;
        while(i>=0 && j>=0)
        {
            if(nums1[i]>=nums2[j]){
                nums1[idx] = nums1[i];
                idx--;
                i--;
            }
            else{
                nums1[idx] = nums2[j];
                idx--;
                j--;
            }
        }
        while(i>=0)
        {
             nums1[idx] = nums1[i];
             idx--;
             i--;
        }
        while(j>=0)
        {
             nums1[idx] = nums2[j];
             idx--;
             j--;
        }
        
    }
};