problem 1:
j=1
for i in range(4):
#print("i="+str(i))
#print("j="+str(j))
for j in range(j):
print("*", end=' ')
j+=4+i*2
print("\n")
problem2:
inputStr=print("Enter STOP if you want to stop!")
inputStr=input("Please enter a string: ")
list=[];
while inputStr.upper()!="STOP" :
list.append(inputStr)
inputStr=input("Please enter a string: ")
size= len(list)
for i in range(size):
if(i== size-1):
print(list[size-i-1])
else:
print(list[size-i-1], end='\t')
print("\n")
problem3:
list=[1,-10,3,5,-99,-57,35,221,4]
list2=[]
for i in list:
if i>=0:
list2.append(i)
for j in list2:
print(j, end=' ')
