from __future__ import print_function ############################# # Author: Aravind Kashyap # File: lis.py # comments: This programme outputs the Longest Strictly Increasing Subsequence in O(NLogN) # Where N is the Number of elements in the list ############################# def CeilIndex(v,l,r,key): while r-l > 1: m = (l + r)/2 if v[m] >= key: r = m else: l = m return r def LongestIncreasingSubsequenceLength(v): if(len(v) == 0): return 0 tail = [0]*len(v) length = 1 tail[0] = v[0] for i in range(1,len(v)): if v[i] < tail[0]: tail[0] = v[i] elif v[i] > tail[length-1]: tail[length] = v[i] length += 1 else: tail[CeilIndex(tail,-1,length-1,v[i])] = v[i] return length v = [2, 5, 3, 7, 11, 8, 10, 13, 6] print(LongestIncreasingSubsequenceLength(v))