Question 4Evaluate the Postfix expression 1 1 1 1 1 1 + + * + *

Sure, let's evaluate the postfix expression step by step.

Postfix notation, also known as Reverse Polish Notation (RPN), is a mathematical notation in which every operator follows all of its operands. The advantage of this notation is that it removes the need for parentheses to indicate the order of operations.

The given postfix expression is: 1 1 1 1 1 1 + + * + *

Here are the steps to evaluate it:

1. Scan the expression from left to right.
2. When you encounter a number, push it into the stack.
3. When you encounter an operator, pop the last two numbers from the stack, perform the operation, and push the result back into the stack.

Let's apply these steps to the given expression:

1. Push all 1s into the stack until you encounter the first operator (+). The stack now looks like this: [1, 1, 1, 1, 1, 1]
2. When you encounter the first '+', pop the last two numbers from the stack (1 and 1), add them, and push the result (2) back into the stack. The stack now looks like this: [1, 1, 1, 1, 2]
3. When you encounter the second '+', pop the last two numbers from the stack (1 and 2), add them, and push the result (3) back into the stack. The stack now looks like this: [1, 1, 1, 3]
4. When you encounter the '*', pop the last two numbers from the stack (1 and 3), multiply them, and push the result (3) back into the stack. The stack now looks like this: [1, 1, 3]
5. When you encounter the next '+', pop the last two numbers from the stack (1 and 3), add them, and push the result (4) back into the stack. The stack now looks like this: [1, 4]
6. When you encounter the final '*', pop the last two numbers from the stack (1 and 4), multiply them, and push the result (4) back into the stack. The stack now looks like this: [4]

So, the result of the given postfix expression is 4.