Project Euler 4

题目

Largest palindrome product

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

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

解决方法

直接枚举所有的三位数和三位数的乘积，然后再判断乘积的值是否为回文字符串即可。

代码

N = 3
ans = 0
for i in range(10**(N-1), 10**N):
    for j in range(10**(N-1), 10**N):
        s = i * j
        if str(s) == str(s)[::-1]:
            ans = max(ans, s)
print(ans)