Given a string of lowercase alphabets and a number k, the task is to print the minimum value of the string after removal of ‘k’ characters. The value of a string is defined as the sum of squares of the count of each distinct character. For example consider the string “saideep”, here frequencies of characters are s-1, a-1, i-1, e-2, d-1, p-1 and value of the string is 1^2 + 1^2 + 1^2 + 1^2 + 1^2 + 2^2 = 9.
Expected Time Complexity : O(n)
Input : str = abccc, K = 1 Output : 6 We remove c to get the value as 12 + 12 + 22 Input : str = aaab, K = 2 Output : 2
Asked In : Amazon
One clear observation is that we need to remove character with highest frequency. One trick is the character ma
A Simple solution is to use sorting technique through all current highest frequency reduce up to k times. For After every reduce again sort frequency array.
A Better Solution used to Priority Queue which has to the highest element on top.
- Initialize empty priority queue.
- Count frequency of each character and Store into temp array.
- Remove K characters which have highest frequency from queue.
- Finally Count Sum of square of each element and return it.
Below is the implementation of the above idea.
Time Complexity: O(n)
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