Shunting-yard

Questions 1 to 5 of 7

1. 1. What is the postfix form of 3 + 4 * 2?

   3 4 + 2 *3 + 4 2 *3 4 2 * ++ 3 * 4 2
2. 2. What does this print, using to_postfix from this lesson? ``python print(to_postfix("12 + 3")) ``

   1 2 3 +12 + 31 2 + 312 3 +
3. 3. Why does 8 - 3 - 2 become 8 3 - 2 - in postfix?

   Because - is applied from right to leftBecause brackets are added around the second -Because the second - has a higher precedence than the firstBecause the first - has the same precedence as the second, so it is popped to the output before the second - is pushed
4. 4. What does this print, using to_postfix from this lesson? ``python print(to_postfix("8 / 4 / 2")) ``

   8 4 / 2 /8 4 2 / /8 2 4 / /8 / 4 / 2
5. 5. When an operator arrives, what are the steps in order?

   Use the arrows to put the steps in order.

   1. 1.Pop each operator that binds at least as tightly into the output, stopping at a ( or an empty stack↑↓
   2. 2.Read the top of the operator stack↑↓
   3. 3.Push the new operator onto the operator stack↑↓