#OK to post homework

#Zidong Zhang, 31/1/2021, Assignment 3



#NewUCG(n):that has the same input and output as UCG(n), but instead starts with the #vector [0$n] and keeps applying NEXG(w), always appending the new guy to the list. #Check that UCG(n)=NewUCG(n) are the same for n from 1 to 14.


NewUCG := proc(n) local N,L,L1:

N:=[]:
L :=[0$n]:
N:=[L]:
L1:=NEXG(L):

while L1 <> FAIL do
	N:=[op(N),L1]:
	L1:= NEXG(L1):

od:
N:
end:



#BoxG(L):that inputs a list of positive integers and outputs a list whose members are the #same as Box(L), but in such an order that when you go from one member to the next, it #only changes in one place

########this question I know how to solve it, but I don't know how to program it since ########I'm not good at recurtion formula.


BoxG := proc(L) local k,i,L1,B1,j:

if not type(L,list) then
  print(L, `should be a list `):
 RETURN(FAIL):
fi:

k:=nops(L):
if k=0 then 
 RETURN([[]]):
fi:
 if not ({seq(type(L[i],integer),i=1..nops(L))}={true} and min(op(L))>=0) then
   print(`bad input`):
  RETURN(FAIL):
 fi:


L1:=[op(1..k-1,L)]:

B1:= BoxG(L1):



end:





#Tomorrow(Date), Yesterday(Date)that inputs four-tupleDate=[DayOfTheMonth , Month , #Year, DayOfTheWeek ]and outputs the dates of the next day, and previous day, #respectively.


###########I don't know how to deal with the week part. ###############


Tomorrow := proc(L) local ndom,nm,ny,nw,dom,m,y,dow:

dom:=L[1]:
m:=L[2]:
y:=L[3]:
dow:=L[4]:



if ( m= odd or m= 8 or m=10 or m=12) then
	if dom +1 > 31 then 
		ndom:=1:
		nm:= m+1:
	else
		ndom:=dom+1:
		nm:=m:
	fi:
elif m=2 then
	if y mod 4 = 0 then
		if dom+1>29 then
			nm:=m+1:
			ndom:= 1:
		else
			nm:=m:
			ndom:=dom+1:
		fi:
	else
		if dom+1>28 then
			nm:= m+1:
			ndom:=1:
		else
			nm:=m:
			ndom:=dom+1:
		fi:
	fi:
else
	if dom +1 > 31 then 
		ndom:=1:
		nm:= m+1:
	else
		ndom:=dom+1:
		nm:=m:
	fi:
fi:
	
if nm>12 then 
	ny:= y+1:
else
	ny:= y:
fi:

[ndom,nm,ny,dow]:
end: