postfix_Expression_Evaluation.cpp

#include<iostream>
#include<math.h>
#include<stack>
using namespace std;


int Post_Expression_Evaluation(string s){

    stack<int> st;
    for (int i = 0; i < s.length(); i++)
    {
       if(s[i]>='0' && s[i]<='9'){

           st.push(s[i]-'0');

       }else{
           int op2=st.top();
           st.pop();

           int op1=st.top();
           st.pop();

           switch (s[i])
           {
           case '+':
               st.push(op1+op2);
               break;
           case '-':
               st.push(op1-op2);
               break;

           case '/':
               st.push(op1/op2);
               break;

           case '*':
               st.push(op1*op2);
               break;
            
           case '^':
               st.push(pow(op1,op2));
               break;
           default:
               break;
           }

       }

    }

    return st.top();
}

int main(){

    cout<<Post_Expression_Evaluation("46+2/5*7+")<<endl;
    return 0;

}