中缀表达式转后缀表达式

Java代码：

栈源码

public class InfixToSuffix {

    public static void main(String[] args) {
        infixToSuffix("(1+3)*(5-7)/9");
    }

    public static void infixToSuffix(String s) {
        ListSimulateStack<Character> stack = new ListSimulateStack<>();
        for (int i = 0; i < s.length(); i++) {
            if (s.charAt(i) >= '0' && s.charAt(i) <='9') {
                System.out.print(s.charAt(i) + " ");
            } else if (s.charAt(i) == '(') {
                stack.push(s.charAt(i));
            } else if (isOper(s.charAt(i))) {
                while (true) {
                    if (stack.isEmpty()) {
                        stack.push(s.charAt(i));
                        break;
                    } else if (priority(s.charAt(i)) > priority(stack.peek())) {
                        stack.push(s.charAt(i));
                        break;
                    } else {
                        System.out.print(stack.pop() + " ");
                    }
                }
            } else if (s.charAt(i) == ')') {
                do {
                    System.out.print(stack.pop() + " ");
                } while (stack.peek() != '(');
                stack.pop();
            }
        }
        while (!stack.isEmpty()) {
            System.out.print(stack.pop() + " ");
        }
    }

    /**
     * 判断是否为运算符
     * @param oper
     * @return
     */
    public static boolean isOper(char oper) {
        return oper == '+' || oper == '-' || oper == '*' || oper == '/';
    }

    /**
     * 使用数字代表运算符的优先级
     * @param oper
     * @return
     */
    public static int priority(char oper) {
        if (oper == '*' || oper == '/') {
            return 1;
        } else if (oper == '+' || oper == '-') {
            return 0;
        } else {
            return -1;
        }
    }
}