refactor: make not ugly

cmd/06/problem/problem.go

@@ -0,0 +1,37 @@
+// Package problem provides models and methods for representing a problem.
+package problem
+
+type Problem interface {
+	Solve() int
+}
+
+type problem struct {
+	operator string
+	operands []int
+}
+
+func From(operator string, operands []int) Problem {
+	return problem{
+		operator: operator,
+		operands: operands,
+	}
+}
+
+func (p problem) Solve() int {
+	result := 0
+
+	switch p.operator {
+	case "+":
+		for _, operand := range p.operands {
+			result += operand
+		}
+	case "*":
+		result = 1
+
+		for _, operand := range p.operands {
+			result *= operand
+		}
+	}
+
+	return result
+}

cmd/06/problem/problem_test.go

@@ -0,0 +1,19 @@
+package problem_test
+
+import (
+	"testing"
+
+	"github.com/StevanFreeborn/advent-of-code-2025/cmd/06/problem"
+)
+
+func TestSolve(t *testing.T) {
+	expected := 6
+	operator := "+"
+	operands := []int{1, 2, 3}
+
+	result := problem.From(operator, operands).Solve()
+
+	if result != expected {
+		t.Errorf("expected %d, got %d", expected, result)
+	}
+}