#include <bits/stdc++.h>
using namespace std;

// 判断字符是否是操作符
bool isOp(string c) {
    return c == "+" || c == "-" || c == "*" || c == "/";
}

string prefixToPostfix(string s) {
    stack<string> stk;
    for (int i = s.size() - 1; i >= 0; i--) {
        string c = string(1, s[i]);
        if (isOp(c)) { // 操作符
            string a = stk.top();
            stk.pop();
            string b = stk.top();
            stk.pop();
            stk.push(a + b + c);
        } else
            stk.push(c); // 字母a~z
    }
    return stk.top();
}

int main() {
    // * + 12 23 * 3 + 45 6
    string prefix = "*+ab*c+de";
    string postfix = prefixToPostfix(prefix);
    cout << "前缀表达式: " << prefix << endl;
    cout << "后缀表达式: " << postfix << endl;
    return 0;
}
/*
Prefix Expression: *+ab*c+de
Postfix Expression: ab+cde+**
Infix Expression: ((a+b)*(c*(d+e)))
*/