Question

我已经编写了以下代码来解决这个话题＆＃34;将一个整数编号重新排列为最大的回文数＆＃34;

示例：

输入数据为485，输出应为＆＃39;不是回文数＆＃39;

输入数据为445，输出应为454

输入数据为24266，输出应为62426（最大回文，而不是26462）

请看一下并帮我纠正这个

我遇到的问题：输入112 - ＆gt;它只返回2

谢谢！

def largest_palindrome(self, number):
        a = list(str(number))
        duplicate = [item for item, count in collections.Counter(a).items() if count > 1]
        if (round(len(a)/2,0) != len(duplicate)):
            print 'Not palindrome number'
        else:
            uniq = []
            max_item = a[0]
            for i in range (1, len (a)):
                if a[i] > max_item:
                    max_item = a[i]
                    uniq=uniq.append(max_item)
            return uniq

Answer 1

import itertools

print "".join(max(x for x in itertools.permutations("100") if x == tuple(reversed(x))))

换句话说：找到所有排列，选择回文，找到最大的排列，并显示它。

Answer 2

from collections import Counter

def largest_palindrome(num):
    # suppose, num is 34347
    c = Counter(str(num))

    # lst is [('4', 2), ('3', 2), ('7', 1)]
    lst = [(k, v) for k, v in c.items()]

    # lst is [('7', 1), ('4', 2), ('3', 2)]
    # we sort, because we want to process the largest digits first
    # to get the largest palindrome
    lst.sort(key=lambda elt: elt[0], reverse=True)

    head = middle = ''
    for k, v in lst:
        if v % 2 == 1:
            # digit, that number is odd, goes to middle, so '7' goes to middle
            if middle:
                # if some digit is already in middle, we can't place
                # another digit there, e. g. for number '1123'
                print('Not palindrome number')
                return
            middle = k

        # if k is '4', v is 2 -> '44'
        # if k is '7', v is 1 -> '7' * (1 // 2) -> '7' * (0) -> ''
        head += k * (v // 2)

    # head is '43', middle is '7'
    return head + middle + head[::-1]

Answer 3

我已经尝试了下面的代码并且它可以正常工作

#Ex1 - Return max proportional number
    def return_arrange(self,number):
        line = list(str(number))
        if len(line)<3:
            print "This number could not be a palindrome number."
            return
        lineA = []
        lineB = []
        i=0        
        while i<len(line):
            for j in range(i+1,len(line)):
                if int(line[i]) == int(line[j]):
                    lineA.append(line[i])
                    line.pop(j)
                    line.pop(i)
                    i=-1
                    break
            if (i>-1):
                lineB.append(line[i])
                line.pop(i)
                i=-1
                if (len(lineB) > 1):
                    print "This number could not be a palindrome number."
                    return
            i=i+1
        lineC = sorted(lineA,reverse=True)+lineB+sorted(lineA)
        return str("".join(lineC))

Python：将整数编号重新排列为最大的回文数

3 个答案: