RosettaCodeData/Task/Longest-increasing-subsequence/Python/longest-increasing-subseque...

34 lines
796 B
Python

def longest_increasing_subsequence(X):
"""Returns the Longest Increasing Subsequence in the Given List/Array"""
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 S[::-1]
if __name__ == '__main__':
for d in [[3,2,6,4,5,1], [0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15]]:
print('a L.I.S. of %s is %s' % (d, longest_increasing_subsequence(d)))