最长递增循环子序列

Question

我有一个寻找最长递增子序列的代码，但是我想扩展它以允许环绕。例如，对于序列（4,5,6,1,2,3），最长的递增循环子序列是（1,2,3,4,5,6），因为一旦我们达到3，我们就可以回到序列的开始（我们只能这样做一次）有人能帮我吗？在

代码如下：

def longest_increasing_subsequence(X):

N = len(X)
P = [0] * N
M = [0] * (N+1)
L = 0
for i in range(N):
   lo = 1
   hi = L
   while lo <= hi:
       mid = (lo+hi)//2
       if (X[M[mid]] < X[i]):
           lo = mid+1
       else:
           hi = mid-1

   newL = lo
   P[i] = M[newL-1]
   M[newL] = i

   if (newL > L):
       L = newL

S = []
k = M[L]
for i in range(L-1, -1, -1):
    S.append(X[k])
    k = P[k]
return len(S[::-1])

Answer 1

只需在每次换班时检查函数的返回值：

max_increasing=longest_increasing_subsequence(X)
for i in range(len(X)-1):
    X=X.append(X.pop(0)) #shift X by 1
    if longest_increasing_subsequence(X)>max_increasing:
         max_increasing=longest_increasing_subsequence(X)

Answer 2

将序列连接到其自身的末尾，然后在其上运行算法。在