题解 | #踩不出足迹

【C.踩不出足迹】打表能发现规律，无论数组是什么，只会出现两种结果，cur=a_1 ^ a_2 ^...^ a_n和对cur逐位取反。
取一个max就行了。

from math import *


n,k = input().split(' ')
n = int(n)
k = int(k)
a = input().split(' ')

def f(cur):
    res = 0
    for i in range(k):
        if (cur & (1<<i)) == 0:
            res = res | (1<<i)
    return res


for i in range(n):
    a[i] = int(a[i])

if n == 1:
    print(a[0])
else:
    cur = a[0]
    for i in range(1, n):
        cur ^= a[i]
    print(max(cur, f(cur)))