题解 | #括号匹配方案#

import java.util.Scanner;
import java.util.Stack;

/**
 * JD15 括号匹配方案
 * @author d3y1
 */
public class Main {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);

        while(in.hasNext()){
            solution1(in);
            // solution2(in);
        }
    }

    /**
     * 模拟法: 栈
     * @param in
     */
    private static void solution1(Scanner in){
        char[] chars = in.nextLine().toCharArray();

        Stack<Character> stack = new Stack<>();
        int result = 1;
        for(char ch: chars){
            if(ch == '('){
                stack.push(ch);
            }else{
                result *= stack.size();
                stack.pop();
            }
        }

        System.out.println(result);
    }

    /**
     * 模拟法: 简化(省略栈)
     * 
     * @param in
     */
    private static void solution2(Scanner in){
        char[] chars = in.nextLine().toCharArray();

        int result = 1;
        int count = 0;
        for(char ch: chars){
            if(ch == '('){
                count++;
            }else{
                result *= count;
                count--;
            }
        }

        System.out.println(result);
    }
}