How to sort an array using minimum number of writes?

Question

My friend was asked a question in his interview:

The interviewer gave him an array of unsorted numbers and asked him to sort. The restriction is that the number of w

Answer 1

The ordering I meant in O(n) is like the selection sort(the previous post) useful when you have a small range of keys (or you are ordering numbers between 2 ranges)

If you have a number array where numbers will be between -10 and 100, then you can create an array of 110 and be sure that all numbers will fit in there, if you consider repeated numbers the idea is the same, but you will have lists instead of numbers in the sorted array

the pseudo-idea is like this

N: max value of your array
tosort //array to be sorted
sorted = int[N]

for i = 0 to length(tosort)
do
   sorted[tosort[i]]++;
end

finalarray = int[length(tosort)]

k = 0
for i = 0 to N
do
  if ( sorted[i] > 0 )
    finalarray[k] = i
    k++;
  endif
end

finalarray will have the final sorted array and you will have o(N) write operations, where N is the range of the array. Once again, this is useful when using keys inside a specific range, but perhaps its your case.

Best regards and good luck!