1722G - Even-Odd XOR - CodeForces Solution

import sys
import random
from bisect import bisect_left as lb
from bisect import bisect_right as rb
from collections import deque
from queue import PriorityQueue as pq
from math import gcd
input_ = lambda: sys.stdin.readline().strip("\r\n")
ii = lambda : int(input_())
il = lambda : list(map(int, input_().split()))
ilf = lambda : list(map(float, input_().split()))
lii = lambda : list(map(int, list(ip())))
ip = lambda : input_()
fi = lambda : float(input_())
ap = lambda ab,bc,cd : ab[bc].append(cd)
li = lambda : list(input_())
pr = lambda x : print(x)
prinT = lambda x : print(x)
f = lambda : sys.stdout.flush()
inv =lambda x:pow(x,mod-2,mod)
dx = [0,0,1,-1,1,1,-1,-1]
dy = [1,-1,0,0,-1,1,1,-1]
mod = 10**9 + 7
mod1 = 998244353

for _ in range(ii()) :
    n = ii()

    a = [0 for i in range (n+4)]
    x = 0
    v = 400

    for i in range (4,n+1) :
        a[i] = v
        x ^= a[i]
        v += 4

    a[1] = 1^x
    a[2] = 2
    a[3] = 3

    for i in range (1,n+1) :
        print(a[i], end = " ")
    print()