This document describes a program to convert infix expressions to postfix expressions in C. It includes an aim to design and implement a program to support parenthesized and non-parenthesized infix expressions with various operators. An algorithm is provided with 4 steps: start, read the infix expression, convert to postfix expression, stop. The C program code implements functions to assign precedence values to operators and operands, a stack to perform the conversion, and takes user input to display the infix and postfix expressions.

1. AIM: Design, Develop and Implement a Program in C for converting an Infix Expression to Postfix
Expression. Program should support for both parenthesized and free parenthesized expressions with the
operators: +, -, *, /, %( Remainder), ^ (Power) and alphanumeric operands.
ALGORITHM:
Step 1: Start.
Step 2: Read an infix expression with parenthesis and without parenthesis.
Step 3: convert the infix expression to postfix expression.
Step 4: Stop
PROGRAM CODE:
#include<stdio.h>
#include<string.h>
#include<conio.h>
int F(char symbol)
{
switch(symbol)
{
case '+' :
case '-':
return 2;
case '*':
case '/':
return 4;
case '^':
case '$':
return 5;
case '(':
return 0;
case '#':
Experiment No.4
Student Name: Vansh Garg UID: 21BCS4548
Branch: Computer Science Section/Group: 21BIT-1/A
Semester: 3rd Date of Performance: 16/09/2022
Subject Name: Data Structure

2. return -1;
default:
return 8;
}
}
int G(char symbol)
{
switch(symbol)
{
case '+':
case '-':
return 1;
case '*':
case '/':
return 3;
case '^':
case '$':
return 6;
case '(':
return 9;
case ')':
return 0;
default:
return 7;
}
}
void infix_postfix(char infix[], char postfix[])
{
int top, j, i;
char s[30], symbol; top = -1;
s[++top] = '#';
j = 0;
for(i=0; i < strlen(infix); i++)
{
symbol = infix[i];
while(F(s[top]) > G(symbol))
{
postfix[j] = s[top--];
j++;
}
if(F(s[top]) != G(symbol))
s[++top] = symbol;
else

3. top--;
}
while(s[top] != '#')
{
postfix[j++] = s[top--];
}
postfix[j] = '0';
}
void main()
{
char infix[20], postfix[20];
printf("nEnter a valid infix expressionn");
scanf("%s",infix);
infix_postfix(infix,postfix);
printf("nThe infix expression is:n");
printf ("%s",infix);
printf("nThe postfix expression is:n");
printf ("%s",postfix);
getch();
}
OUTPUT: