This expression tree is for scientific mode for the problem 3*4+6/2+2*5 is:
To do the problem with an expression tree you need to collapse the nodes (numbers) with there operators (such as *,+,and/).
This is how it looks after you've done the first collapsing. You see that the 3,4,and * are gone? That's because the way you collapse is do the numbers against there operator so that you come out with the answer .
This is what you get after you do the 2nd collapsing. This time do you see the difference? Yep the /,6, and 2 are gone because I did the same thing except I divided them instead of multiplying them.
This is what you get after the 3rd collapsing and its easy to spot the difference right? Well if you can't the 12,3,and the + are gone and there is a 15. That's because there was a + above the 12 and the 3 so I added them together.
This is the easiest difference to spot of all. The 10 and 15 and the + are gone and there instead there is a 25.That's because the + was above the 10 and 15 so I added them together.
Here is the assembly program to evaluate the above expression tree:
; 3 * 4 + 6 / 2 + 2 * 5
mul ebx ; This collapses 3 * 4 to 12 into eax
mov ecx,eax ; This moves eax into ecx temporarily
div ebx ; This collapses 6 / 2 to 3 into eax
add ecx,eax ; This collapses 3 * 4 and 6 / 2 together into 15
mul ebx ; This collapses 2 * 5 to 10 into eax
add eax,ecx ; This collapses 15 and 10 into 25
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