# How do I convert infix to postfix?

## How do I convert infix to postfix?

To convert infix expression to postfix expression, we will use the stack data structure. By scanning the infix expression from left to right, when we will get any operand, simply add them to the postfix form, and for the operator and parenthesis, add them in the stack maintaining the precedence of them.

**What is postfix infix in C++?**

Infix expression is an expression in which the operator is in the middle of operands, like operand operator operand. Postfix expression is an expression in which the operator is after operands, like operand operator. Postfix expressions are easily computed by the system but are not human readable.

**How will you apply stack in converting infix to postfix using C write a program to implement the same?**

Stack | Set 2 (Infix to Postfix)

- Scan the infix expression from left to right.
- If the scanned character is an operand, output it.
- Else,
- If the scanned character is an ‘(‘, push it to the stack.
- If the scanned character is an ‘)’, pop the stack and output it until a ‘(‘ is encountered, and discard both the parenthesis.

### How will you apply stack in converting infix to postfix using C?

Algorithm to convert Infix To Postfix Push “(“onto Stack, and add “)” to the end of X. Scan X from left to right and repeat Step 3 to 6 for each element of X until the Stack is empty. If an operand is encountered, add it to Y. If a left parenthesis is encountered, push it onto Stack.

**How do I convert infix to prefix manually?**

Rules for the conversion of infix to prefix expression:

- First, reverse the infix expression given in the problem.
- Scan the expression from left to right.
- Whenever the operands arrive, print them.
- If the operator arrives and the stack is found to be empty, then simply push the operator into the stack.

**How can you convert an infix expression to postfix expression using stack give one example?**

Algorithm

- Step 1 : Scan the Infix Expression from left to right.
- Step 2 : If the scanned character is an operand, append it with final Infix to Postfix string.
- Step 3 : Else,
- Step 3.2 : Else, Pop all the operators from the stack which are greater than or equal to in precedence than that of the scanned operator.

## What is the infix expression?

Infix notation: X + Y. Operators are written in-between their operands. This is the usual way we write expressions. An expression such as A * ( B + C ) / D is usually taken to mean something like: “First add B and C together, then multiply the result by A, then divide by D to give the final answer.”

**How can you convert an infix expression to postfix expression using stack give an example?**

Scan the expression from left to right. If we encounter any operand in the expression, then we push the operand in the stack….Example 1: Postfix expression: 2 3 4 * +

Input | Stack | |
---|---|---|

2 3 4 * + | empty | Push 2 |

3 4 * + | 2 | Push 3 |

4 * + | 3 2 | Push 4 |

* + | 4 3 2 | Pop 4 and 3, and perform 4*3 = 12. Push 12 into the stack. |

**How do you solve infix to prefix?**

We use the same to convert Infix to Prefix.

- Step 1: Reverse the infix expression i.e A+B*C will become C*B+A. Note while reversing each ‘(‘ will become ‘)’ and each ‘)’ becomes ‘(‘.
- Step 2: Obtain the “nearly” postfix expression of the modified expression i.e CB*A+.
- Step 3: Reverse the postfix expression.

### How is postfix expression calculated?

Following is an algorithm for evaluation postfix expressions.

- Create a stack to store operands (or values).
- Scan the given expression and do the following for every scanned element. …..a) If the element is a number, push it into the stack.
- When the expression is ended, the number in the stack is the final answer.

**When using the stack to convert the below given expression from infix to postfix?**

Algorithm to Convert Infix to Postfix Expression Using Stack Initialize the Stack. Scan the operator from left to right in the infix expression. If the leftmost character is an operand, set it as the current output to the Postfix string.