Question

Consider the stack operations:

push 4
push 7
push 8
add
push 10
sub
mul
What is the content of the stack after each instruction execution?
a) [4, 7, 8, 15, 5, 10, 50]
b) [4, 7, 8, 15, -5, 10, 50]
c) [4, 7, 8, 15, 10, 10, 50]
d) [4, 7, 8, 15, 5, -10, 50]

Answer 1

After executing the defined stack operations, the sequence of instructions results in modifying the stack multiple times, ending with a single value [20] left on the stack. None of the specified answers a through d matches the correct resulting content of the stack.

Step-by-step explanation:

The stack operations described are a series of instructions that modify the contents of the stack. Each operation is applied sequentially. Initially, the stack is empty. Let's go through each operation one by one.

• push 4: Stack becomes [4].
• push 7: Stack becomes [4, 7].
• push 8: Stack becomes [4, 7, 8].
• add: Pops the top two values, adds them, and pushes the result onto the stack. So 7 + 8 = 15, and the stack becomes [4, 15].
• push 10: Stack becomes [4, 15, 10].
• sub: Pops the top two values, subtracts the second from the first, and pushes the result onto the stack. 15 - 10 = 5, and the stack becomes [4, 5].
• mul: Pops the top two values, multiplies them, and pushes the result onto the stack. 4 * 5 = 20, and the stack becomes [20].

After all instructions are executed, the final content of the stack is just [20].