C＃为什么我的DECIMAL否定？

Question

here is how i call the following function:

    List<decimal> numbers = new List<decimal>();

    numbers.Add(210m);
    numbers.Add(188.83m);
    numbers.Add(67.93m);
    numbers.Add(125.92m);
    numbers.Add(35.92m);
    numbers.Add(19.16m);
    numbers.Add(98.48m);



    List<decimal> listresult = FindSumSubset(9075.12m, numbers);

** * ** * ** * *** the function *

List<decimal> FindSumSubset(decimal sum, List<decimal> list)
            {
               for (int i = 0; i < list.Count; i++)
               {
                  decimal value = list[i];
                  if (sum - value == 0.0m)
                  {
                      return new List<decimal> { value };
                  }
                  else
                  {
                      var subset = FindSumSubset(sum - value, list.GetRange(i + 1, list.Count-1 -i));
                      if (subset != null)
                      {
                          subset.Add(value);
                          return subset;


                      }
                  }
               }
               return null;
            }

when i run in debug mode, the decimal sum is giving me a huge negative value like -93435.34

how can this be happening?

Answer 1

Try making this change:

if (sum - value <= 0.0m)

The problem is that sum-value is not exactly 0 so it just keeps recursing forever.

Also, I think you want to remove the for loop. You don't need it if you recurse.

Answer 2

你满溢而未检查是我的猜测。