Scribd
Upload
5 views2 pages

Infix To Postfix

This C code implements a function to convert infix expressions to postfix notation. It defines operator precedence and uses a stack to manage operators and parentheses during the conversion process. The main function demonstrates the conversion with a sample infix expression and prints the resulting postfix expression.

Uploaded by

akshathashetty
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as TXT, PDF, TXT or read online on Scribd
5 views2 pages

Infix To Postfix

This C code implements a function to convert infix expressions to postfix notation. It defines operator precedence and uses a stack to manage operators and parentheses during the conversion process. The main function demonstrates the conversion with a sample infix expression and prints the resulting postfix expression.

Uploaded by

akshathashetty
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as TXT, PDF, TXT or read online on Scribd
You are on page 1/ 2

// C code to convert infix to postfix expression

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_EXPR_SIZE 100

// Function to return precedence of operators


int precedence(char operator)
{
switch (operator) {
case '+':
case '-':
return 1;
case '*':
case '/':
return 2;
case '^':
return 3;
default:
return -1;
}
}

// Function to check if the scanned character


// is an operator
int isOperator(char ch)
{
return (ch == '+' || ch == '-' || ch == '*' || ch == '/'
|| ch == '^');
}

// Main functio to convert infix expression


// to postfix expression
char* infixToPostfix(char* infix)
{
int i, j;
int len = strlen(infix);
char* postfix = (char*)malloc(sizeof(char) * (len + 2));
char stack[MAX_EXPR_SIZE];
int top = -1;

for (i = 0, j = 0; i < len; i++) {


if (infix[i] == ' ' || infix[i] == '\t')
continue;

// If the scanned character is operand


// add it to the postfix expression
if (isalnum(infix[i])) {
postfix[j++] = infix[i];
}

// if the scanned character is '('


// push it in the stack
else if (infix[i] == '(') {
stack[++top] = infix[i];
}
// if the scanned character is ')'
// pop the stack and add it to the
// output string until empty or '(' found
else if (infix[i] == ')') {
while (top > -1 && stack[top] != '(')
postfix[j++] = stack[top--];
if (top > -1 && stack[top] != '(')
return "Invalid Expression";
else
top--;
}

// If the scanned character is an operator


// push it in the stack
else if (isOperator(infix[i])) {
while (top > -1
&& precedence(stack[top])
>= precedence(infix[i]))
postfix[j++] = stack[top--];
stack[++top] = infix[i];
}
}

// Pop all remaining elements from the stack


while (top > -1) {
if (stack[top] == '(') {
return "Invalid Expression";
}
postfix[j++] = stack[top--];
}
postfix[j] = '\0';
return postfix;
}

// Driver code
int main()
{
char infix[MAX_EXPR_SIZE] = "a+b*(c^d-e)^(f+g*h)-i";

// Function call
char* postfix = infixToPostfix(infix);
printf("%s\n", postfix);
free(postfix);
return 0;
}

You might also like