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python - 有人可以向我解释为什么这段代码不起作用吗？

问题描述

annual_salary = int(input("Your annual salary "))
semi_annual_raise = 0.07
r = 0.04
down_payment = 250000
epsilon = 100
low = 0
high = 10000
guess = (high + low)//2
best_saving_rate = (guess/10000)
months = 0
current_savings = 0
steps = 0

while abs(current_savings - down_payment) >= 100:
    for i in range(36):
        current_savings += best_saving_rate*(annual_salary/12) + (current_savings*r)/12
        months +=1
        if months%6 == 0:
            annual_salary = annual_salary + semi_annual_raise*annual_salary  
    if current_savings < down_payment:
        low = guess
    else:
        high = guess
    steps += 1
    guess = (high + low)//2
    best_saving_rate = float(guess/10000)
print(steps)
print(best_saving_rate)
print(current_savings)

该代码应该为试图在 36 个月内有足够的钱支付 250000 美元的人找到最佳储蓄率。我使用二分搜索，我认为我在正确的轨道上，但它不会工作。我认为问题在于可变电流节省不会在每次迭代时重新初始化，我不知道如何让它做到这一点。请帮忙。

标签： pythonpython-3.xbisection

解决方案

为什么您期望每次迭代都current_savings将其重置为？0您没有在代码中这样做，那么什么会导致这种情况发生呢？同样从代码的外观来看，您也应该重置months为0（尽管看起来for循环索引变量i实际上应该是月份）。

这修复了我可以看到的明显错误：

while abs(current_savings - down_payment) >= 100:
    current_savings = 0   # add this
    for month in range(36):  # Change this
        current_savings += best_saving_rate * (annual_salary / 12) + (current_savings * r) / 12
        # months += 1  <-- remove this
        if months % 6 == 0:

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