I have problem to solve:
There is a set of N integers in range [-1000, 1000], N< 1000
I have to find if there is any subset which sum of elements is exactly S.
S is an integer in range [-1 000 000, 1 000 000 ]

Example:

Set - {5, 10, 25, 50}
S = 30
I can find a subset {5,25} - 5+25 = 30

Set - { -6,9,100,-45}
S = -42
I can find a subset {-6,9,-45} - (-6)+9+(-45) = 3 + (-45) = (-42)

Set - {-5, 10, 20, 100}
Set = 3
I can't find any set which sum is exacly 3.

Please help