Question

我有一个代码可以找到列表的所有循环，例如对于[1,2,3]循环是[1,2,3]，[2,3,1]，[3,1， 2]。我还有一个代码，用于查找增长最长的子序列。

我想要做的是输入一个列表，找到该列表的每个周期中增长最长的子序列，然后从所有这些中返回最大长度。如何从这两个函数中找到每个循环的LIS，然后返回最大值？

到目前为止，这是我的代码：

def cycles(X):

  n = len(X)

  values = []

  for i in range(0,n):
    values.append(X[i:n] + X[0:i])

  return values    



def longest_increasing_subsequence(d):

    l = []

    for i in range(len(d)):

        l.append(max([l[j] for j in range(i) if l[j][-1] < d[i]] or  [[]], key=len)  + [d[i]])


    return len(max(l, key=len))

我很感激任何帮助。感谢。

Answer 1

这将完成这项工作：

l=[1,2,3,4]
s=cycles(l)
lis=[longest_increasing_subsequence(d) for d in s]
print(lis) 
print(max(lis))

结果是

[4,3,2,3]

和

Answer 2

试试这段代码：

l = [3,4,5,9,8,1,2,7,7,7,7,7,7,7,6,0,1]
empty = []
one = [1]
two = [2,1]
three = [1,0,2,3]
tricky = [1,2,3,0,-2,-1]
ring = [3,4,5,0,1,2]
internal = [9,1,2,3,4,5,0]

# consider your list as a ring, continuous and infinite
def longest_increasing_subsequence(l):
    length = len(l)
    if length == 0: return 0  # list is empty
    i, tmp, longest = [0, 1, 1]
    # 1 < tmp means that ring is finished, but the sequence continue to increase
    while i < length or 1 < tmp:
        # compare elements on the ring
        if l[i%length] < l[(i+1)%length]:
            tmp += 1
        else:
            if longest < tmp: longest = tmp
            tmp = 1
        i += 1
    return longest

print("0 == " + str(longest_increasing_subsequence(empty)))
print("1 == " + str(longest_increasing_subsequence(one)))
print("2 == " + str(longest_increasing_subsequence(two)))
print("3 == " + str(longest_increasing_subsequence(three)))
print("5 == " + str(longest_increasing_subsequence(tricky)))
print("5 == " + str(longest_increasing_subsequence(internal)))
print("6 == " + str(longest_increasing_subsequence(ring)))
print("6 == " + str(longest_increasing_subsequence(l)))

最大增长序列的最大值

2 个答案: