King Kohima problem:  King Kohima has reserved a new exclusive street for his executive class employees where they can build their homes. He has assigned you to plan that street. You have to decide on which plots along the street are new building allowed to be built. In order to this, you first want to calculate the number of possible ways of assigning free plots to buildings while keeping in mind this restriction  No two consecutive plots can have buildings on them. This is done to ensure a sense of free space in the arena. The street is divided in M sections. Each section corresponds to 2 plots, one on each side of the street. Find the number of possible assignments.  InputIn the first line youre given M ( M  1000 ). Output In the first and only line output the result/ Example Input: 3 Output: 25 Example explanation: If we just look at the one street side and mark X as a plot where building is allowed and Y as a free plot, we have: XYX, YXY, YYX, XYY, YYY. Since the same number exists on the other side, we have 5*5 = 25 combinations.  For example, if the input is 3, then only five layouts (YYY, YYX, YXY, XYY, XYX) of the eight possible combinations (YYY, YYX, YXX, YXY, XYY, XYX, XXY, XXX) are valid.  For both sides of the street, it's 5*5=25.Please critique this solution.def binary(i):    r=str(0)    while(i):        x=str(i%2)        if(x=='1' and r[-1]=='1'): #two consecutive X are not possible             return None        else:            r=r+str(x)        i=i/2    return r    m=3 #inputl=[]for i in range(0,2**m):    l.append(binary(i)) #converted the number to binaryprint(l)c=0 #count possible plot availablefor i in l:    if i:        c=c+1print(c*c) #both side of the lane
Solution to King Kohima problem in Python
python;programming challenge;combinatorics;time limit exceeded