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