Discussion About Print BST keys in the given range

#1

This is Discussion thread about Print BST keys in the given range

#2 
list1=[]
for i in range(int(input())):
	n=int(input())
	num=list(map(int,input().split()))
	a,b=map(int,input().split())
	for i in range(b):
		if(num[i] >=a and num[i]<=b):
			list1.append(num[i])
print("# Preorder : ", end="")
for k in num:
	print(k , end=" ")

print("")
print("# Nodes within range are : ", end="")
list1.sort()
for j in list1:
	print(j, end=" ")

why this code is not working