code javascript:

Count the minimum number of integers that must be deleted from an array so that no two integers occur the same number of times.

Task description

An array A consisting of N integers is given. Our goal is to obtain an array in which every value occurs a unique number of times. We only consider integers that appear at least once in the resulting array. To achieve the goal, we can delete some integers from A$.$ What is the minimum number of integers that must be deleted from A so that every remaining value occurs a unique number of times?

Write a function:

function solution$($A$)$;

that, given an array A consisting of N integers, returns the minimum number of integers that must be deleted from it so that every remaining value occurs a unique number of times.

Examples:

$1.$ Given A $=[1,1,1,2,2,2],$ the function should return $1.$ We can delete one occurrence of $1$ or one occurrence of $2.$ After this operation, one value will occur three times and the other one two times.

$2.$ Given A $=[5,3,3,2,5,2,3,2],$ the function should return $2.$ After deleting number $3$ twice, the remaining elements of the array are $[5,2,5,2,3,2].$ In this array no two numbers occur the same number of times.

$3.$ Given A $=[127,15,3,8,10],$ the function should return $4.$ All elements of the array occur exactly once. We have to delete all but one element.

$4.$ Given A $=[10000000,10000000,5,5,5,2,2,2,0,0],$ the function should return $4.$

Write an efficient algorithm for the following assumptions:

$$ N is an integer within the range $[1.\mathrm{.}200,000]$;

$$ each element of array A is an integer within the range $[0.\mathrm{.}1,000,000,000].$