python中二分法与控制流练习

Question

问题遇到的现象和发生背景

假设我要买一栋房子总价total_cost为1000000元，要求首付portion_down_payment比例为25%。目前我刚毕业，储蓄current_saving为0，通过合理投资我每年的利率回报为0.04，并且每个月都可以拿到利润回报加入到储蓄中。同时我预期入职后半年的工资上涨幅度semi_annual_raise为0.07，即半年后我每个月的工资比之前多7%。
要求询问我的年薪annual_salary，运用二分法得出每个月工资投入储蓄的比例saved_percent，使得我在三年后储蓄能够支付房子的首付，允许误差epsilon为100.

问题相关代码，请勿粘贴截图

semi_annual_raise = 0.07
annual_rate = 0.04
total_cost = 1000000
portion_down_payment = total_cost*0.25

annual_salary = float(input("enter your starting salary:"))
monthly_salary = annual_salary/12
saved_percent = 0
monthly_saving = monthly_salary*saved_percent
current_saving = 0
numMonth = 0

epsilon = 100
low = 0
high = 1
saved_percent = (low + high)/2
done = False
numGuesses = 0

while not done == True:
while numMonth <= 36:
current_saving = current_saving*(1+annual_rate/12) + monthly_saving
numMonth += 1
if numMonth % 6 == 0:
monthly_salary *= (1 + semi_annual_raise)

if abs(current_saving - portion_down_payment)>= epsilon:
    if current_saving < portion_down_payment:
        low = saved_percent 
    else:
        high = saved_percent 
    saved_percent = (low + high)/2
    numGuesses += 1
    numMonth = 0
else :
    done = True
    

print("Best saving rate is", saved_percent)
print("Steps in bisection search:", numGuesses)

运行结果及报错内容

中途无法继续运行

我的解答思路和尝试过的方法

我想要达到的结果

如果该代码思路可行，希望能够在这个基础上进行修改

Answer 1

修改如下：

semi_annual_raise = 0.07
annual_rate = 0.04
total_cost = 1000000
portion_down_payment = total_cost*0.25

annual_salary = float(input("enter your starting salary:"))
monthly_salary = annual_salary/12
saved_percent = 0
current_saving = 0
numMonth = 0

epsilon = 100
low = 0
high = 1
saved_percent = (low + high)/2
done = False
numGuesses = 0

while not done == True:
    while numMonth <= 36:
        monthly_saving = monthly_salary*saved_percent
        current_saving = current_saving*(1+annual_rate/12) + monthly_saving
        numMonth += 1
        if numMonth % 6 == 0:
            monthly_salary *= (1 + semi_annual_raise)
    if abs(current_saving - portion_down_payment)>= epsilon:
        if current_saving < portion_down_payment:
            low = saved_percent 
        else:
            high = saved_percent 
        saved_percent = (low + high)/2
        monthly_salary = annual_salary/12
        current_saving = 0
        numGuesses += 1
        numMonth = 0
    else :
        done = True
    
print("Best saving rate is", saved_percent)
print("Steps in bisection search:", numGuesses)

试运行结果：

enter your starting salary:120000
Best saving rate is 0.531982421875
Steps in bisection search: 11