All possible combinations in a list of numbers AND adding a value to each combination result to reach a target value

Python Help
1

Please help.

I found a couple of code examples that partially do what I need (see below). Can you please help me modify either code to do what I need?

I need to find all the combinations in a list of numbers and to each combination to substract (or add, multiply, or divide) a value AND then to find which result sums to a specific value.

For example:

  1. Here is a number list: 10, 12, 3, 4, 8
  2. And here is the value I want to substract from each combination: 5
  3. And here is the final target value (product) to find (only the combinations that give this result should be printed): 7

So the computation should be (I’m giving only the general idea since the actual list could be potentially longer):

10 - 5 = 5
10 + 12 - 5 = 17
10 + 12 + 3 - 5 = 20
10 + 12 + 3 + 4 - 5 = 24
10 + 12 + 3 + 4 + 8 - 5 = 32
12 - 5 = 7
12 + 3 - 5 = 10
12 + 3 + 4 - 5 = 14
12 + 3 + 4 + 8 - 5 = 22
3 - 5 = -2
3 + 4 - 5 = 2
3 + 4 + 8 - 5 = 10
4 - 5 = -1
4 + 8 - 5 = 7

And the only combinations that should “print” are:

12 - 5 = 7
4 + 8 - 5 = 7

Here are the two sample codes that I found and partially do what I need:

def subset_sum(numbers, target, partial=[]):
    s = sum(partial)

    # check if the partial sum is equals to target
    if s == target:
        print("sum(%s)=%s" % (partial, target))
    if s >= target:
        return  # if we reach the number why bother to continue

    for i in range(len(numbers)):
        n = numbers[i]
        remaining = numbers[i + 1:]
        subset_sum(remaining, target, partial + [n])


if __name__ == "__main__":
    subset_sum([10, 12, 3, 4, 8], 7)

and the second one:

class Solution(object):
   def combinationSum(self, candidates, target):
      result = []
      unique={}
      candidates = list(set(candidates))
      self.solve(candidates,target,result,unique)
      return result
   def solve(self,candidates,target,result,unique,i = 0,current=[]):
      if target == 0:
         temp = [i for i in current]
         temp1 = temp
         temp.sort()
         temp = tuple(temp)
         if temp not in unique:
            unique[temp] = 1
            result.append(temp1)
         return
      if target <0:
         return
      for x in range(i,len(candidates)):
         current.append(candidates[x])
         self.solve(candidates,target-candidates[x],result,unique,i,current)
         current.pop(len(current)-1)
ob1 = Solution()
print(*ob1.combinationSum([10, 12, 3, 4, 8],7), sep='\n')

In advance, thank you for any help provided. I’m new to Python as you can tell.