AI+Python快速解决税务筹划问题

import pulp

# 税档数据（起点, 终点, 税率）
brackets = [
    (0, 30000, 0.05),
    (30000, 90000, 0.10),
    (90000, 300000, 0.20),
    (300000, 500000, 0.30),
    (500000, 2000000, 0.35)  # 最后一档无上限，设为200万近似处理
]

# 每档使用上限作为每人可分配利润
upper_bounds = [high for (_, high, _) in brackets]  # 单位：元
rates = [rate for (_, _, rate) in brackets]
quick_deductions = [0, 1500, 10500, 40500, 65500]

# 每档真实人均税负 = 上限 * 税率 - 速算扣除
avg_tax_per_person = [
    upper_bounds[i] * rates[i] - quick_deductions[i]
    for i in range(5)
]

# 输入参数
total_profit = 3.2e8
num_A = 220
num_B = 180

num_micro = 15
profit_micro = 2_500_000

num_pref = 6
profit_pref = 20_000_000

normal_ratio_limit = 0.3  # 普通企业利润不能超过其余的30%

# 固定公司利润
fixed_micro_total = num_micro * profit_micro
fixed_pref_total = num_pref * profit_pref

# 创建问题
prob = pulp.LpProblem("Global_Tax_Minimization", pulp.LpMinimize)

# 合伙企业人数变量（整数）
x_A = [pulp.LpVariable(f"A_{i}", lowBound=0, cat='Integer') for i in range(5)]
x_B = [pulp.LpVariable(f"B_{i}", lowBound=0, cat='Integer') for i in range(5)]

# 普通企业利润变量（连续）
normal_profit = pulp.LpVariable("Normal_Profit", lowBound=0, cat='Continuous')

# 合伙企业总利润（使用上限）
M_expr = pulp.lpSum([(x_A[i] + x_B[i]) * upper_bounds[i] for i in range(5)])

# 公司总利润 = 固定 + 普通企业部分
N_expr = fixed_micro_total + fixed_pref_total + normal_profit

# 约束：M + N = 总利润
prob += M_expr + N_expr == total_profit, "Total_Profit_Constraint"

# 人数约束
prob += pulp.lpSum(x_A) == num_A, "Total_A_Count"
prob += pulp.lpSum(x_B) == num_B, "Total_B_Count"

# 限制普通企业利润不超过其余部分的30%
prob += normal_profit <= normal_ratio_limit * (fixed_micro_total + fixed_pref_total), "Normal_Profit_Limit"

# 目标函数：个人所得税最小化
tax_expr = (
    pulp.lpSum([x_A[i] * avg_tax_per_person[i] for i in range(5)]) +
    pulp.lpSum([x_B[i] * avg_tax_per_person[i] for i in range(5)]) +
    fixed_micro_total * (1 - 0.05) * 0.2 +
    fixed_pref_total * (1 - 0.15) * 0.2 +
    normal_profit * (1 - 0.25) * 0.2
)

# 目标函数：综合税赋（企业所得税 + 个人所得税）
# tax_expr = (
#     # 合伙企业（只算个税）
#     pulp.lpSum([x_A[i] * avg_tax_per_person[i] for i in range(5)]) +
#     pulp.lpSum([x_B[i] * avg_tax_per_person[i] for i in range(5)]) +

#     # 小微企业税 + 分红税
#     fixed_micro_total * 0.05 + fixed_micro_total * (1 - 0.05) * 0.2 +

#     # 优惠企业税 + 分红税
#     fixed_pref_total * 0.15 + fixed_pref_total * (1 - 0.15) * 0.2 +

#     # 普通企业税 + 分红税
#     normal_profit * 0.25 + normal_profit * (1 - 0.25) * 0.2
# )


prob += tax_expr

# 求解
prob.solve()

# 输出结构化结果
print(f"状态: {pulp.LpStatus[prob.status]}")
M_total = pulp.value(M_expr)
N_total = pulp.value(N_expr)
tax_total = pulp.value(tax_expr)

# 各部分税负
tax_partnership = sum(pulp.value(x_A[i]) * avg_tax_per_person[i] for i in range(5)) + \
                  sum(pulp.value(x_B[i]) * avg_tax_per_person[i] for i in range(5))
tax_corp_dividend = (
    fixed_micro_total * (1 - 0.05) * 0.2 +
    fixed_pref_total * (1 - 0.15) * 0.2 +
    pulp.value(normal_profit) * (1 - 0.25) * 0.2
)

print(f"\n✅ 合伙企业利润 M: {M_total/1e8:.4f} 亿元")
print(f"✅ 公司企业利润 N: {N_total/1e8:.4f} 亿元")

print("\n📊 公司企业利润结构：")
print(f"小微企业利润（{num_micro} 个 × {profit_micro/1e6:.1f} 万）: {fixed_micro_total/1e8:.4f} 亿元")
print(f"优惠企业利润（{num_pref} 个 × {profit_pref/1e6:.1f} 万）: {fixed_pref_total/1e8:.4f} 亿元")
print(f"普通企业利润（限制 ≤ {normal_ratio_limit*100:.1f}%）: {normal_profit.varValue/1e8:.4f} 亿元")

print(f"\n💰 总个人所得税额: {tax_total / 1e8:.4f} 亿元")
print(f"├─ 合伙企业个税: {tax_partnership / 1e8:.4f} 亿元")
print(f"└─ 公司股东分红个税: {tax_corp_dividend / 1e8:.4f} 亿元")

# 新增：企业所得税结构与综合税额
corp_tax_micro = fixed_micro_total * 0.05
corp_tax_pref = fixed_pref_total * 0.15
corp_tax_normal = pulp.value(normal_profit) * 0.25
corp_tax_total = corp_tax_micro + corp_tax_pref + corp_tax_normal

total_tax = tax_total + corp_tax_total

print(f"\n🏢 企业所得税总额: {corp_tax_total / 1e8:.4f} 亿元")
print(f"├─ 小微企业: {corp_tax_micro / 1e8:.4f} 亿元")
print(f"├─ 优惠企业: {corp_tax_pref / 1e8:.4f} 亿元")
print(f"└─ 普通企业: {corp_tax_normal / 1e8:.4f} 亿元")

print(f"\n📊 综合税赋总额（企业税 + 个税）: {total_tax / 1e8:.4f} 亿元")

# 打印合伙企业结构
print("\n🧑‍💼 合伙企业人员分配结构（单位：万元）：")
profit_A = 0
profit_B = 0
for i in range(5):
    a_num = pulp.value(x_A[i])
    b_num = pulp.value(x_B[i])
    a_profit = a_num * upper_bounds[i]
    b_profit = b_num * upper_bounds[i]
    total = a_profit + b_profit
    profit_A += a_profit
    profit_B += b_profit
    total_people = a_num + b_num
    avg_per_person = total / total_people if total_people > 0 else 0

    print(f"税档{i+1}：A类 {a_num:.0f}人，利润 {a_profit/1e4:.2f} 万元 | "
          f"B类 {b_num:.0f}人，利润 {b_profit/1e4:.2f} 万元 | "
          f"总计: {total/1e4:.2f} 万元 | 人均: {avg_per_person:,.0f} 元")

print(f"\nA类合伙企业分配总利润: {profit_A/1e8:.4f} 亿元")
print(f"B类合伙企业分配总利润: {profit_B/1e8:.4f} 亿元")