Find missing element in an array.

Question

Given an array of size N-1 such that it only contains distinct integers in the range of 1 to N. Find the missing element. 
 Example 1: 
 Input: N = 5 A[] = {1,2,3,5} Output: 4

Stefan Helzle · Accepted Answer

a!localVariables(
 local!list: {1,2,3,5},
 difference(1 + enumerate(max(local!list)), local!list)
)

Peter Lewis · Answer

Just swap max(local!list) with your actual maximum number - try this: 
 a!localVariables(
 local!maxNumber: 6,
 local!list: {1, 2, 3, 4, 5},
 difference(1 + enumerate(local!maxNumber), local!list)
)

Amaan Shekh · Answer

alternate approach -> a!localVariables(
 local!list: { 1, 2, 3, 4, 5, 6, 9, 8, 10, 11 },
 local!n: length(local!list) + 1,
 (local!n * (local!n + 1)) / 2 - sum(local!list)
)

Find missing element in an array.

Top Replies