fds10.txt

#include<iostream>
#include<cstring>
#include<stack>
using namespace std;
int getWeight(char ch)
{
switch (ch) 
 {
case '/':
case '*': return 2;
case '+':
case '-': return 1;
default : return 0;
}
}
void infix2postfix(char infix[], char postfix[], int size)
{
stack<char> s;
int weight;
int i = 0;
int k = 0;
char ch;
while (i < size) 
 {
ch = infix[i];
if (ch == '(') 
 {
s.push(ch);
i++;
continue;
}
if (ch == ')') 
 {
while (!s.empty() && s.top() != '(') 
 {
postfix[k++] = s.top();
s.pop();
}
if (!s.empty()) 
 {
s.pop();
}
i++;
continue;
}
weight = getWeight(ch);
if (weight == 0) 
 {
postfix[k++] = ch;
}
else 
 {
if (s.empty()) 
 {
s.push(ch);
}
else
 {
while (!s.empty() && s.top() != '(' && weight <= 
getWeight(s.top())) 
 {
postfix[k++] = s.top();
s.pop();
}
s.push(ch);
}
}
i++;
}
while (!s.empty()) 
 {
postfix[k++] = s.top();
s.pop();
}
postfix[k] = 0;
}
int main() 
{
char infix[100];
cout<<"\nENter Infix Operation:";
cin>>infix;
int size = strlen(infix);
char postfix[size];
infix2postfix(infix,postfix,size);
cout<<"\nInfix Expression :: "<<infix;
cout<<"\nPostfix Expression :: "<<postfix;
cout<<endl;
return 0;
}