Problem Descrption:
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.Constraints:
nums1.length == m + nnums2.length == n0 <= m, n <= 2001 <= m + n <= 200-109 <= nums1[i], nums2[j] <= 109
Problem Link :Merge Sorted Array – LeetCode
Solutions:
Java Code:
public void merge(int[] nums1, int m, int[] nums2, int n) {
//nums1 index(actual nums array)
int nums1Ptr=m-1;
//nums2 index
int nums2Ptr=n-1;
//nums1 index(next filled position-)
int resultPtr=m+n-1;
//traverse the nums2 array
while(nums2Ptr>=0){
//if nums1[nums1Ptr]>nums2[nums2Ptr], it is the largest among two arrays, store it at
//resultPtr position of nums1
if(nums1Ptr>=0 && nums1[nums1Ptr]>nums2[nums2Ptr]){
nums1[resultPtr]=nums1[nums1Ptr];
resultPtr--;
nums1Ptr--;
}
//if nums1[nums1Ptr]<nums2[nums2Ptr] or there is no element left in nums1 array and we
//just need to push all the remaining elements of nums2 array into nums1 array
else{
nums1[resultPtr]=nums2[nums2Ptr];
resultPtr--;
nums2Ptr--;
}
}
}Complexity:
- Time-Complexity: O(m+n)
- Space-Complexity: O(1)
Hello, my name is Deependra Singh. I hold B.tech degree in Computer Science & Engineering from Institute of Engineering & Technology, Lucknow. Currently, I am working in Steel Authority of India Limited as a Software Developer.