MergedSortedArray.jav

/**
 *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.
 *
 * 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.
 *
 */

public class MergedSortedArray
{
    class Solution
    {
        public void merge(int[] nums1, int m, int[] nums2, int n)
        {
            //get the last index of both arrays
            int i = m - 1;
            int j = n - 1;
            //get the last index of combined array
            int index = m + n - 1;

            //loop through both arrays from the last value and compare them
            while(j >= 0) //while nums2 still has uncheck values
            {
                //compare last values in nums1 and nums2
                if( i >= 0 && nums1[i] > nums2[j])
                {
                    //assign the greater value to last index in combined array
                    nums1[index] =  nums1[i];
                    i--; //move to the next index
                }
                else
                {
                    //thesame logic like in the if statement above
                    nums1[index] = nums2[j];
                    j--;
                }
                //move to the next index in combined array
                index--;
            }

        }
    }
}