Module target_sum

Source

Functionsยง

find_target_sum_ways
find_target_sum_ways2
analysis and dp sum(P) - sum(N) = target sum(P) + sum(N) + sum(P) - sum(N) = target + sum(P) + sum(N) 2 * sum(P) = target + sum(nums) so, if target + sum(nums) is not even, return 0, else get sum(P) == (target + sum(nums))/2