Challenge Name

C++11 @manuel

1. Approch to Solving the problem

Given a set of numbers ranging from 0 to N-1 with one missing number, then the largest number in that set is the length of the array.

If we find the sum of N + (N-1) + (N - 2) + ... + (N - N) = N * (N + 1) / 2, and then iterate through the given set and subtract this value, once we reach the end of the array the difference will be the missing number.

2. How to compile and run this code

make
make test 
make clean

3. How this program works

Single line of input -> Single line of output 1,3,4,0 -> 2