有人可以向我解释为什么这段代码不起作用吗？

Question

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)

This code is supposed to find the best saving rate for someone who is trying to have enough money for a payment of 250000 dollars in 36 months. I use bisection search and I think I'm in the right track but it won't work. I think the problem is that the variable current savings is not reinitializing with every iteration and I do not know how to make it do that. PLEASE HELP.

Answer 1

Why are you expecting the current_savings to be reset to 0 with every iteration? You do not do that in the code, so what would cause that to happen? Also by the looks of the code, you should be resetting months to 0 as well (though it appears that the for loop index variable i should actually be the month).

This fixes the obvious errors that I could see:

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: