实现月度预算结转计算

solve()

Carryover (max 20% of limit):
  BDG-0001: remaining=158.99 carry=158.2 max=158.2
  BDG-0002: remaining=0.0 carry=0 max=200.4
  BDG-0003: remaining=7.55 carry=0 max=40.8
  BDG-0004: remaining=170.41 carry=170.41 max=197.0
  BDG-0005: remaining=22.35 carry=22.35 max=60.4
  BDG-0006: remaining=38.8 carry=32.2 max=32.2
  BDG-0007: remaining=22.6 carry=22.6 max=53.8
  BDG-0008: remaining=52.14 carry=44.0 max=44.0