Given two arrays a and b, we need to build an array c such that every element c[i] of c contains a value from a which is greater than b[i] and is closest to b[i]. If a has no greater element than b[i], then value of c[i] is -1. All arrays are of same size.
Input : a = [ 2, 6, 5, 7, 0] b = [1, 3, 2, 5, 8] Output : c = [2, 5, 5, 7, -1] Input : a = [ 2, 6, 5, 7, 0] b = [0, 2, 3, 5, 1] Output : c = [2, 5, 5, 6, 2]
Naive Approach : For each element in b, we traverse the whole of a and try to find the closest greater element, and save the result for each search. This will cost time complexity of O(n^2).
Efficient Approach : Sort the array a, and for each b[i], apply binary search in sorted array a. For this method our time complexity will be O(nlogn).
Note: For closest greater element we can use upper_bound().
Below is the implementation.
Result = 5 2 1 6 5 -1
- Find closest greater value for every element in array
- Closest greater or same value on left side for every element in array
- Find closest value for every element in array
- Find closest smaller value for every element in array
- Smallest element greater than X not present in the array
- Elements greater than the previous and next element in an Array
- Adding elements of an array until every element becomes greater than or equal to k
- Rearrange an array such that every odd indexed element is greater than it previous
- Sum of elements in an array with frequencies greater than or equal to that element
- First strictly greater element in a sorted array in Java
- Count the number of elements which are greater than any of element on right side of an array
- Find element in a sorted array whose frequency is greater than or equal to n/2.
- Minimum element whose n-th power is greater than product of an array of size n
- Replace each element by the difference of the total size of the array and frequency of that element
- Range Query on array whose each element is XOR of index value and previous element
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to email@example.com. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.
Improved By : sanjeev2552