C++ 中缀表达式转后缀表达式（单一位数运算数）

#include #include #include using namespace std;

int main() { string infix; cin >> infix;

stack<char> op_stack;
string postfix = "";

for (char c : infix) {
    if (isdigit(c)) {
        postfix += c;
    } else {
        while (!op_stack.empty() && op_stack.top() != '(' && ((c == '*' || c == '/') || (op_stack.top() == '+' || op_stack.top() == '-'))) {
            postfix += op_stack.top();
            op_stack.pop();
        }
        op_stack.push(c);
    }
}

while (!op_stack.empty()) {
    postfix += op_stack.top();
    op_stack.pop();
}

cout << postfix << endl;
return 0;

}