Prefix to Infix.cpp

// C++ Program to convert prefix to Infix
#include <iostream>
#include <stack>
using namespace std;

// function to check if character is operator or not
bool isOperator(char x) {
switch (x) {
case '+':
case '-':
case '/':
case '*':
case '^':
case '%':
	return true;
}
return false;
}

// Convert prefix to Infix expression
string preToInfix(string pre_exp) {
stack<string> s;

// length of expression
int length = pre_exp.size();

// reading from right to left
for (int i = length - 1; i >= 0; i--) {

	// check if symbol is operator
	if (isOperator(pre_exp[i])) {

	// pop two operands from stack
	string op1 = s.top(); s.pop();
	string op2 = s.top(); s.pop();

	// concat the operands and operator
	string temp = "(" + op1 + pre_exp[i] + op2 + ")";

	// Push string temp back to stack
	s.push(temp);
	}

	// if symbol is an operand
	else {

	// push the operand to the stack
	s.push(string(1, pre_exp[i]));
	}
}

// Stack now contains the Infix expression
return s.top();
}

// Driver Code
int main() {
string pre_exp = "*-A/BC-/AKL";
cout << "Infix : " << preToInfix(pre_exp);
return 0;
}