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							- import smtplib
 
- from email.mime.text import MIMEText
 
- from email.header import Header
 
- """
 
-     回溯算法(试探法)
 
-     在搜索尝试过程中寻找问题的解,当发现已不满足求解条件时,就“回溯”返回,尝试别的路径。回溯法是一种选优搜索法,按选优条件向前搜索,以达到目标。但当探索到某一步时,发现原先选择并不优或达不到目标,就退回一步重新选择,这种走不通就退回再走的技术为回溯法,而满足回溯条件的某个状态的点称为“回溯点”。
 
-     回溯算法解决问题的
 
-     针对所给问题,定义问题的解空间,它至少包含问题的一个(最优)解。
 
-     确定易于搜索的解空间结构,使得能用回溯法方便地搜索整个解空间 。
 
-     以深度优先的方式搜索解空间,并且在搜索过程中用剪枝函数避免无效搜索。
 
- """
 
- class StockTest(object):
 
-     """
 
-         栈练习
 
-     """
 
-     def queen(self, A, cur=0):
 
-         """
 
-             八皇后问题
 
-         :param A:
 
-         :param cur:
 
-         :return:
 
-         """
 
-         if cur == len(A):
 
-             print(A)
 
-             # return 0
 
-         else:
 
-             for col in range(len(A)):
 
-                 A[cur], flag = col, True
 
-                 # 判断当前与之前的所有是否规则冲突
 
-                 for row in range(cur):
 
-                     if A[row] == col or abs(col - A[row]) == cur - row:
 
-                         flag = False
 
-                         break
 
-                 if flag:
 
-                     self.queen(A, cur + 1)
 
-     def movingCount(self, threshold, rows, cols):
 
-         "产生 0 矩阵 "
 
-         board = [[0 for i in range(cols)] for j in range(rows)]
 
-         global acc
 
-         acc = 0
 
-         "下标之和,若大于threshold则TRUE,否则Folse"
 
-         def block(r, c):
 
-             s = sum(map(int, str(r) + str(c)))
 
-             return s > threshold
 
-         def traverse(r, c):
 
-             global acc
 
-             if not (0 <= r < rows and 0 <= c < cols):  # 超出角标范围挑出
 
-                 return
 
-             if board[r][c] != 0:  # 不等于0 跳出
 
-                 return
 
-             if board[r][c] == -1 or block(r, c):
 
-                 board[r][c] = -1  # 超出门限的点记录-1
 
-                 return
 
-             board[r][c] = 1  # 符合规定的点记录1,并计数加一
 
-             acc += 1
 
-             traverse(r + 1, c)
 
-             traverse(r - 1, c)
 
-             traverse(r, c + 1)
 
-             traverse(r, c - 1)
 
-         traverse(0, 0)
 
-         return acc
 
-     def bubble_sort(self, numbers):
 
-         """
 
-             时间复杂度:O(n^2)
 
-         :param numbers:
 
-         :return:
 
-         """
 
-         n = len(numbers)
 
-         for i in range(n):
 
-             for j in range(0, n - i - 1):
 
-                 if numbers[j] > numbers[j + 1]:
 
-                     numbers[j], numbers[j + 1] = numbers[j + 1], numbers[j]
 
-         return numbers
 
-     def choose_sort(self, numbers):
 
-         """
 
-             选择排序,时间复杂度O(n^2)
 
-         :param numbers:
 
-         :return:
 
-         """
 
-         n = len(numbers)
 
-         for i in range(n):
 
-             min_index = i
 
-             min_value = numbers[i]
 
-             for j in range(i + 1, n):
 
-                 if min_value > numbers[j]:
 
-                     min_value = numbers[j]
 
-                     min_index = j
 
-             if min_index != i:
 
-                 numbers[min_index] = numbers[i]
 
-                 numbers[i] = min_value
 
-         return numbers
 
-     def insert_sort(self, numbers):
 
-         """
 
-             插入排序,时间复杂度O(n^2)
 
-         :return:
 
-         """
 
-         n = len(numbers)
 
-         for i in range(1, n):
 
-             insert_index = i - 1
 
-             insert_value = numbers[i]
 
-             while insert_index >= 0 and insert_value < numbers[insert_index]:
 
-                 numbers[insert_index + 1] = numbers[insert_index]
 
-                 insert_index -= 1
 
-             if insert_index + 1 != i:
 
-                 numbers[insert_index + 1] = insert_value
 
-         return numbers
 
-     def shell_sort(self, numbers):
 
-         """
 
-             希尔排序,时间复杂度O(n^2)
 
-         :param numbers:
 
-         :return:
 
-         """
 
-         n = len(numbers)
 
-         gap = int(n / 2)
 
-         while gap > 0:
 
-             for i in range(gap, n):
 
-                 temp = numbers[i]
 
-                 j = i
 
-                 while j >= gap and numbers[j - gap] > temp:
 
-                     numbers[j] = numbers[j - gap]
 
-                     j -= gap
 
-                 numbers[i] = temp
 
-             gap = int(gap / 2)
 
-         return numbers
 
-     def quick_sort(self, numbers):
 
-         """
 
-             快速排序,时间复杂度O(n^2)
 
-         :param numbers:
 
-         :return:
 
-         """
 
-         if len(numbers) <= 1:
 
-             return numbers
 
-         pivot = numbers[int(len(numbers) / 2)]
 
-         left = [x for x in numbers if x < pivot]
 
-         middle = [pivot]
 
-         right = [x for x in numbers if x > pivot]
 
-         return self.quick_sort(left) + middle + self.quick_sort(right)
 
-     def merge_sort(self, numbers):
 
-         """
 
-             归并排序
 
-         :param numbers:
 
-         :return:
 
-         """
 
-         pass
 
-     def radix_sort(self, numbers):
 
-         """
 
-             基数排序,时间复杂度O(n*k)
 
-         :param number:
 
-         :return:
 
-         """
 
-         # 记录当前正在排拿一位,最低位为1
 
-         i = 0
 
-         max_num = max(numbers)
 
-         # 记录最大值的位数
 
-         j = len(str(max_num))
 
-         while i < j:
 
-             # 初始化桶数组
 
-             bucket_list = [[] for _ in range(10)]
 
-             for x in numbers:
 
-                 # 找到位置放入桶数组
 
-                 bucket_list[int(x / (10 ** i)) % 10].append(x)
 
-             numbers.clear()
 
-             # 放回原序列
 
-             for x in bucket_list:
 
-                 numbers.extend([a for a in x])
 
-             i += 1
 
-         return numbers
 
-     def send_mail(self):
 
-         sender = '1285211525@qq.com'
 
-         receivers = '1285211525@qq.com'
 
-         message = MIMEText('Python 邮件发送测试...', 'plain', 'utf-8')
 
-         message['From'] = Header('binren')
 
-         message['To'] = Header('zhangbr')
 
-         subject = 'test mail'
 
-         message['Subject'] = Header(subject, 'utf-8')
 
-         try:
 
-             stmp_obj = smtplib.SMTP('localhost')
 
-             stmp_obj.sendmail(sender, receivers, message.as_string())
 
-             print('send successful')
 
-         except Exception as e:
 
-             print(e)
 
- if __name__ == '__main__':
 
-     st = StockTest()
 
-     nums = [1, 2, 5, 3, 1, 101, 10, 1111, 2]
 
-     print(st.send_mail())
 
 
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