# -*- coding: utf-8 -*- 
# @Time : 2018/3/23 16:50 
# @Author : Lv Zhangrun 
# @Site :  
# @File : CreateExercise.py 
# @Software: PyCharm
import random

operators_list = ["+", "-", "*", "÷"]
operators_dict = {"+": 0, "-": 0, "*": 1, "÷": 1}
max_number = 10
operators_count = 3


def createExerciseList(operators_count, exercise):
    if operators_count > 0:
        temp = []
        if len(exercise) == 0:  # 总列表为空时，要插入第一个随机数
            temp.append(random.randint(1, max_number))  # 插入第一个操作数
            temp.append(operators_list[random.randint(0, 3)])  # 插入操作符
        else:
            temp.insert(0,
                        exercise.pop())  # 获取总列表里[[1,"+",2]]或[[[1,"+",2],"*",3]]唯一一组组好的列表，形如[1,"+",2]或者[[1,"+",2],"*",3]，插到组装列表temp,temp再加入一个运算符，
            temp.append(operators_list[random.randint(0, 3)])  # 插入操作符
            # temp=addBrackets(temp)
        temp.append(random.randint(1, max_number))  # 插入第二个操作数
        # print("temp:"+str(temp))
        exercise.append(temp)  # 将组成好的，形如[1,"+",2]添加进总列表
        # print(str(operators_count) + ":" + str(exercise[0]))
        operators_count = operators_count - 1  # 操作符数量减1
        return createExerciseList(operators_count, exercise)
    else:
        return exercise


def getExercises(exercise_list, exercise_str_list):
    if type(exercise_list[0]) == list:
        # print(exercise_list)
        for i in range(len(exercise_list[0]) - 1):
            temp = exercise_list[0].pop()
            exercise_str_list.append(temp)
        return getExercises(exercise_list[0], exercise_str_list)
    else:
        exercise_str_list.append(exercise_list[0])
        return exercise_str_list


if __name__ == '__main__':

    for k in range(10):
        exercise = []  # 总列表，形如想生成3*2÷4，就是[[[3, '*', 2], '÷', 4]]
        exercise_str_list = []  # 用来解析总列表，比如把[[[3, '*', 2], '÷', 4]]解析成[4,'÷',2,'*',3]
        exercise_str = ''
        # exercise_list = createExerciseList(operators_count, exercise)
        exercise = createExerciseList(random.randint(1, 5), exercise)
        exercise = getExercises(exercise, exercise_str_list)

        for i in range(len(exercise)):
            last = str(exercise.pop())
            exercise_str = exercise_str + last
        print(exercise_str)

        # random_number=random.randint(0,max_number)
        # print(operators_list[random_number])