Last Updated: 10 Dec, 2020
Replace Each Element Of Array With Its Corresponding Rank
Easy
Asked in companies
Given an array of integers 'ARR’ of size ‘N’. Replace each element of this array with its corresponding rank and return the array.
The rank of an element is an integer between 1 to ‘N’ inclusive that represents how large the element is in comparison to other elements of the array. The following rules can also define the rank of an element:
1. It is an integer starting from 1.
2. The larger the element, the larger the rank. If two elements are equal, their rank must be the same.
3. It should be as small as possible.
For Example:
'ARR' = [4, 7, 2, 90]
Here, 2 is the smallest element, followed by 4, 7, and 90.
Hence rank of element 2 is 1, element 4 is 2, element 7 is 3, and element 90 is 4.
Hence we return [2, 3, 1, 4].
Input Format :
The first line contains an integer ‘N’ representing the number of elements in ‘ARR’.
The second line contains ‘N’ space-separated integers representing the elements present in ‘ARR’.
Output Format :
Print space-separated elements of ‘ARR’ where the value at index ‘i’ is replaced by the rank of the element at index ‘i’ in ‘ARR’.
Note :
You do not need to print anything it has already been taken care of. Return the integer array ‘ARR’ after replacing every element with its rank.
Approaches
- First, make an array ‘temp’ of size ‘N’ and copy all the elements of ’ARR’ in it.
- Run a loop where ‘i ranges from 0 to N-1 -:
1. Declare a HashMap and initialise a variable ‘rank’= 1
2. Iterate over array ‘temp’ and increment ‘rank’ by one whenever we find an element in ‘temp’ which is strictly less than ‘ARR[i]’ and not present in HashMap. After that insert the element in HashMap.
3. Replace the value in ‘ARR[i]’ with ‘rank’. - Return the array ‘ARR’.
- First, make an array ‘temp’ of size ‘N’ and copy all the elements of ’ARR’ in it.
- Sort the array ‘temp’ in non-decreasing order.
- Create a HashMap that will map each element with its rank.
- Initialize a variable ‘rank’ := 1.
- Run a loop where ‘i’ ranges from 0 to N-1. For each ‘i’ If ‘temp[i]’ is not present in HashMap then insert the key ‘temp[i]’ in HashMap and map its value with ‘rank’ and after that increment the variable ‘rank’ by 1.
- Iterate over the array ‘ARR’ and replace each element with its corresponding value in HashMap.
- Return the array ‘ARR’.
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