Submission #3012782

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Source Code Expand

n, x = map(int, input().split())


def calc(a):
    b = []
    for i in range(len(a)-2):
        b.append(list(sorted(a[i:i+3]))[1])
    if len(b) == 1:
        return b[0]
    else:
        return calc(b)
"""
n = 5
max_ = []
for i in range(n):
    max_.append(i*2+1)

for i in range(n-1, 0, -1):
    max_.append(i*2)

print(calc(max_))
"""

if x == 1 or x == 2*n-1:
    print("No")
    exit()
print("Yes")

if x == 2:
    center = 2
    r1 = 1
    r2 = 3
    l = 4
else:
    center = x
    r1 = x+1
    r2 = 1
    l = 2

ans = []
y = 1
for i in range(n-2):
    while y in [center, r1, r2, l]:
        y+= 1
    ans.append(y)
    y+=1
ans.append(l)
ans.append(center)
ans.append(r1)
ans.append(r2)
for i in range(n-3):
    while y in [center, r1, r2, l]:
        y+=1
    ans.append(y)
    y+=1
if n == 2:
    ans = [1,2,3]
for x in ans:
    print(x)

Submission Info

Judge Result