class Solution {
    public void merge(int[] nums1, int m, int[] nums2, int n) {
        if(m == 0){                             // First check if 'm' is 0 or not
            for(int i = 0; i < n; i++)          // If Yes, then run a loop that traverse 'n' times
                nums1[i] = nums2[i];            // And add all the elements of 'nums2' to 'nums1'
        }
                                                // Else, first initialize some variables
        int i = m-1;                            // A var to point the (m-1)th index of the 'nums1' array
        int j = n-1;                            // A var to point the last index of the 'nums2' array
        int k = m+j;                            // A var to point the last index of the 'nums1' array
        
        while(i >= 0 && j >= 0){                // Now, run a loop till both 'i' and 'j' is not 0
            if(nums1[i] > nums2[j]){            // Check, if the 'i'th element of 'nums1' is greater than the 'j'th element of 'nums2' or not
                nums1[k] = nums1[i--];          // If Yes, then update the 'k'th element of 'nums1' with the 'i'th element of 'nums1'
            }
            else{                               // Else
                nums1[k] = nums2[j--];          // Update the 'k'th element of 'nums1' with the 'j'th element of 'nums2'
            }
            k--;                                // Decrease 'k' to move to the previous index
        }
        
        while(j >= 0)                           // If 'j' is still greater than 0; then it means that not all the elements of 'nums2' are not added to 'nums1'
            nums1[k--] = nums2[j--];            // So, keep adding them to the 'k'th element of 'nums1'
    }
}