Nested while loop

Question

m = 0
x = 1
while x < 4:
y = 1
while y < 3:
m = m + x + y
y = y + 1
x = x + 1
print(m)

My solution as follows:
m=0
x=1
y=1
1<3
m=0+1+1
m=2
y=y+1
y=2
x=1+1
x=2
m=2
x=2
y=2
2<3
m=0+2+2
m=4
y=2+1
y=3
x=2+1
x=3
m=4
x=2
y=3
2<4
m=4+2+3
m=9
y=3+1
y=4
x=2+1
x=3
m=9+3+4
m=16
The output is 21.
I got output 16?

Answer 1

You missed the fact that y = 1 every time you start an iteration in the first while. So in every iteration of the first while y gets the same value 1.
You can define y outside while so that it gets higher value every iteration.

Answer 2

The inner loop satisfied when x=3. After it moves to outer loop where value for x=3, y=1 and m’s value changed as well? Sorry trying to understand the syntax. Please help!

Answer 3

Here some notes on your solution, you can see where exactly there is a problem. I hope it will help.

m=0
x=1
y=1
1<3
m=0+1+1
m=2
y=y+1
y=2
#here you shouldn't go outside while until the condition y<3 becomes false.
(x=1+1)#You shouldn't do that yet, you still in second while that means x still 1 and you go to the next iteration of the second while.
x=2 #x=1
m=2
x=2
y=2
2<3
m=0+2+2 # here m has the value 2 so you should keep it and do m=2+x+y = 2+1+2 (don't forget x is 1 not 2)
m=4 #m=5
y=2+1
y=3
x=2+1#same thing you don't get that until you exit the second while
x=3
m=4
x=2
y=3# if y ==3 you don't execute any iteration of the second while cause 3<3 is a false statement. After that all operations in the second while are ignored.
2<4
m=4+2+3 #not done cause you already exited the second while
m=9
y=3+1
y=4 #same thing 4 is greater than 3 so you ignore the operations you did with false condition
x=2+1
x=3
m=9+3+4
m=16

So you'll exit the first while when y==2 and the first while when x==3.Finally you print m.

Answer 4

Finally found my mistake! Thank you so much for your help👍

Answer 5

You are welcome ! Good luck 👍