Euler #3

[Reason7194]

Hey everyone, i have a problem with my code to solve Project Euler #4: ( not #3! )

Code: Select all

L = 0
for x in range(100, 1000):
   for y in range(100, 1000):
           product = x*y
          if str(product) == str(product)[::-1]:
         L = product
print L

I know it prints out the wrong palindromic because it is the last palindromic from the loops. How do i find the largest one though? a print max(L) does not work

[jgreen45]

Append all the palindromes you find to a list then use max to find the largest?

[Phantom Wolf]

Your indentation was outright wrong. You should always use four spaces and absolutely no tabs. If you haven't already, I suggest reading PEP 8.

To address your problem, it always printed out the result of the last sequence because you wire directly assigning the result to L each time. So, every time the loop ran, the old result was forgotten. I fixed this by making L into a list, and appending the result each loop. That way, all the results are remembered.

Code: Select all

L = []
for x in range(100, 1000):
    for y in range(100, 1000):
        product = x*y
        if str(product) == str(product)[::-1]:
            L.append(product)
print max(L)

[Reason7194]

Ah thanks! That makes perfect sense.