Problem 4:Largest palindrome product

原题地址:http://projecteuler.net/problem=4

Largest palindrome product

Problem 4

A palindromic number reads the same both ways. The largest palindrome made from the product of two 2-digit numbers is 9009 = 91 99.

Find the largest palindrome made from the product of two 3-digit numbers.


大意是:

一个回文数指的是从左向右和从右向左读都一样的数字。最大的由两个两位数乘积构成的回文数是9009 = 91 * 99.

找出最大的有由个三位数乘积构成的回文数。



解法1:

从两个最大三位数之积开始,如果是回文数,则看看能不能分解成两个三位数之积,如果能则跳出循环。

python代码如下所示:

def isHuiWen(number):
    return number == number[::-1]



topNumber = 999*999
max = 999
min = 100
flag = False

while topNumber > 1E2:
    if isHuiWen(str(topNumber)):
       for i in range(max,min-1,-1):
        
                if   topNumber%i == 0 and \
                    topNumber//i <= max:
                    flag = True
                    break
                
    if flag:
         break
    topNumber = topNumber-1
    
print i
print topNumber



注:题目的中文翻译源自http://pe.spiritzhang.com

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