Python For Loop Homework-CodePudding

So this question isn't hard by any means but just worded in a confusing way. I've tried 3 solutions, and none of them are correct. I've given my genuine effort, so I hope someone else can help me out here. Here's the question:

Using a for loop, write the following program: all the two-digit numbers which are equal to double the product of the digits that make up the given number are displayed in a column."

Here are the 3 solutions I've tried so far:

num = int(input("Enter a two-digit number: "))
digitArr = []

for i in str(num):
    digitArr.append(i)

result = 1

for j in digitArr:
    result = result * int(j)
result = result ** 2 #here

for i in range(10, 100):
    tempDigitArr = []
    for j in str(i):
        tempDigitArr.append(j)
    tempResult = 1
    for k in tempDigitArr:
        tempResult = tempResult * int(k)
    tempResult = tempResult ** 2 #here
    if tempResult == result:
        print(i)
        tempResult = 1
        continue
    else:
        tempResult = 1
        continue

num = int(input("Enter a two-digit number: "))
digitArr = []

for i in str(num):
    digitArr.append(i)

result = 1

for j in digitArr:
    result = result * int(j)
result = result ** 2 #here

for i in range(10, 100):
    tempDigitArr = []
    for j in str(i):
        tempDigitArr.append(j)
    tempResult = 1
    for k in tempDigitArr:
        tempResult = tempResult * int(k)
    tempResult = tempResult ** 2 #here
    if tempResult == result:
        print(i)
        tempResult = 1
        continue
    else:
        tempResult = 1
        continue

num = int(input("Enter a two-digit number: "))
digitArr = []

for i in str(num):
    digitArr.append(i)

result = 1

for j in digitArr:
    result = result * int(j)

for i in range(10, 100):
    tempDigitArr = []
    for j in str(i):
        tempDigitArr.append(j)
    tempResult = 1
    for k in tempDigitArr:
        tempResult = tempResult * int(k)
    if tempResult == result:
        print(i)
        tempResult = 1
        continue
    else:
        tempResult = 1
        continue

And yes, if anyone's wondering; my course is using an auto-check system ;-;

CodePudding user response：

The methodology is pretty straightforward

test = range(10,99)

for num in test:

    prod = 1
    for digit in str(num): prod = prod * int(digit)

    if num == 2*prod:
        print(num)

Fun fact: only 36 qualifies for this requirement

CodePudding user response：

IIUC, you want:

for i in range(10, 100):
    tens, units = divmod(i, 10)
    if tens*units*2 == i:
        print(i)

CodePudding user response：

I'm not giving you code (others did so already anyway) but rather explain what (I think) is wrong with your program:

you say the program is auto-graded, but the question does not say anything about input, so I guess that by expecting input your program just waits forever for input that is never provided; instead you probably just need the for num in range(10, 100) loop at the bottom
if you do the same calculation twice (which you do not need, see above, but if), you should define a function using def, not copy the code
the question asks about the number being double the product of its digits, not the square, i.e.use *2, not **2
and you should compare that double-product to the number itself, not to the product of that first (not asked for) input-number
since you know it's a two-digit number, you do not actually have to loop over the digits but can access them directly using integer(!)-division // and modulo %

I'm sure you'll get it right with those hints (and without just copying the full code).

CodePudding user response：

If I understand the requirement correctly, the given number is to be obtained from the user and the two digit numbers have to match it (not themselves):

number = int(input("given number: "))

for n in range(10,100):
    d,u = divmod(n,10)
    if d*u*2 == number:
        print(n)

Sample run:

given number: 36
29
36
63
92