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学生成绩管理系统.zip(免费下载)[48 次下载]class Node(object): |
def __init__(self, data, pointer): |
self.data = data |
self.next = pointer |
# 创建单链表 |
class SingleLinkedList(object): |
def __init__(self): |
self.head = Node(None, None) |
self.point = self.head |
def append(self, data): |
# 末尾追加节点 |
new_node = Node(data, None) |
self.point.next = new_node |
self.point = new_node |
def insert(self, data, find): |
# 插入数据(前向插入数据) |
if not self.head.next: |
print('链表为空') |
return None |
new_node = Node(data, None) |
self.point = self.head |
while self.point.next.data != find: |
self.point = self.point.next |
if self.point.next is None: |
print('没有找到该元素') |
return None |
new_node.next = self.point.next |
self.point.next = new_node |
def delete(self, find): |
# 删除节点 |
# 空链表 |
if not self.head.next: |
print('链表为空') |
return None |
self.point = self.head |
while self.point.next.data != find: |
self.point = self.point.next |
pointer = self.point.next |
self.point.next = self.point.next.next |
del pointer |
def insert_after_head(self, data): |
node = Node(data, None) |
# bug 产生没写 if 返回 |
if not self.head.next: |
self.head.next = node |
return None |
node.next = self.head.next |
self.head.next = node |
def reverse(self): |
local_list = SingleLinkedList() |
self.point = self.head |
count = 0 |
while self.point.next: |
count += 1 |
self.point = self.point.next |
data = self.point.data |
local_list.insert_after_head(data) |
return local_list |
def get_size(self): |
count = 0 |
self.point = self.head |
while self.point.next: |
self.point = self.point.next |
count += 1 |
return count |
def delete_by_tail(self, num): |
size = self.get_size() |
assert (num <= size) |
assert (num > 0) |
pos = size - num |
count = 0 |
self.point = self.head |
while count < size: |
count += 1 |
self.point = self.point.next |
if count == pos: |
pointer = self.point.next |
self.point.next = self.point.next.next |
del pointer |
# 求中间节点 只允许遍历一次 |
def quick_middle(self): |
slow_point = self.head |
fast_point = self.head |
while fast_point.next.next: |
slow_point = slow_point.next |
fast_point = fast_point.next.next |
if not fast_point.next: |
break |
if fast_point.next: |
slow_point = slow_point.next |
return slow_point.data |
def check_circle(self): |
pass |
def sort(self): |
# get_size()改变了 self.point 的指向 |
length = self.get_size() |
i, j = 0, 0 |
flag = 1 |
while i < length: |
self.point = self.head.next |
while j < length - i - 1: |
if self.point.data > self.point.next.data: |
temp = self.point.data |
self.point.data = self.point.next.data |
self.point.next.data = temp |
self.point = self.point.next |
j += 1 |
flag = 0 |
if flag: |
break |
i += 1 |
j = 0 |
def print(self): |
# 打印结点 |
self.point = self.head |
while self.point.next: |
self.point = self.point.next |
print('{} ->'.format(self.point.data), end=' ') |
print('') |
class StudentControlSystem(SingleLinkedList): |
# 打印菜单 |
def print_menu(self): |
print('*' * 30) |
print('-' * 13 + '菜单' + '-' * 13) |
print('1.增加学生信息') |
print('2.删除学生信息') |
print('3.修改学生信息') |
print('4.查找学生信息') |
print('5.显示所有信息') |
print('6.排序') |
print('0.退出程序') |
print('*' * 30) |
# 用户输入 |
def user_input(self, item): |
try: |
item = int(item) |
except: |
pass |
# 增加信息 |
if item == 1: |
self.add_info() |
# 删除信息 |
elif item == 2: |
find = input('请输入删除的学号：') |
self.del_info(find=find) |
# 修改信息 |
elif item == 3: |
self.modify_info() |
# 查找信息 |
elif item == 4: |
self.search_info() |
# 显示信息 |
elif item == 5: |
self.display_info() |
# 信息排序 |
elif item == 6: |
self.rank_info() |
# 退出程序 保存数据 |
elif item == 0: |
with open('database.txt', 'w') as f: |
self.point = self.head |
while self.point.next: |
self.point = self.point.next |
f.writelines('{}\n'.format(self.point.data)) |
exit() |
else: |
print('请输入正确的数字') |
# id 保证互异性 |
def unique_id(self, std_id): |
self.point = self.head |
while self.point.next: |
self.point = self.point.next |
if self.point.data['id'] == std_id: |
return False |
return True |
# 增加信息 |
def add_info(self): |
# id 不能重复 |
# 成绩不能超出范围 |
name = input('姓名：') |
std_id = input('学生id：') |
while not self.unique_id(std_id=std_id): |
print('id重复') |
std_id = input('学生id：') |
grade = input('学生成绩：') |
if eval(grade) < 0 or eval(grade) > 100: |
print('超出范围') |
grade = input('学生成绩：') |
print(name, std_id, grade) |
print('请确认无误后保存') |
choice = input('y/n') |
items = ['y', 'yes', 'Y', 'Yes'] |
if choice in items: |
print(choice) |
data = {'id': std_id, 'name': name, 'grade': grade} |
self.append(data) |
# 删除信息 |
def del_info(self, find): |
print('请确认无误后保存') |
choice = input('y/n') |
items = ['y', 'yes', 'Y', 'Yes'] |
if choice in items: |
if not self.head.next: |
print('链表为空') |
return None |
self.point = self.head |
while self.point.next.data['id'] != find: |
self.point = self.point.next |
pointer = self.point.next |
self.point.next = self.point.next.next |
del pointer |
# 序列逆序 |
def reverse(self): |
local_list = StudentControlSystem() |
self.point = self.head |
count = 0 |
while self.point.next: |
count += 1 |
self.point = self.point.next |
data = self.point.data |
local_list.insert_after_head(data) |
return local_list |
# 序列排序 |
def sort(self, item): |
length = self.get_size() |
i, j = 0, 0 |
flag = 1 |
while i < length: |
self.point = self.head.next |
while j < length - i - 1: |
if int(self.point.data[item]) > int(self.point.next.data[item]): |
# self.point.data, self.point.next.data = |
# self.point.next.data, self.point.data |
temp = self.point.data |
self.point.data = self.point.next.data |
self.point.next.data = temp |
self.point = self.point.next |
j += 1 |
flag = 0 |
if flag: |
break |
i += 1 |
j = 0 |
# 修改信息 |
def modify_info(self): |
find = input('输入需要修改的学生的id：') |
if not self.head.next: |
print('链表为空') |
return None |
self.point = self.head |
while str(self.point.next.data['id']) != find: |
self.point = self.point.next |
if self.point.next is None: |
print('没有找到该元素') |
return None |
name = input('姓名：') |
grade = input('学生成绩：') |
self.point.next.data['name'] = name |
self.point.next.data['grade'] = grade |
# 搜索信息 |
def search_info(self): |
find = input('输入需要查找的学生的id：') |
if not self.head.next: |
print('链表为空') |
return None |
self.point = self.head |
while str(self.point.next.data['id']) != find: |
self.point = self.point.next |
if self.point.next is None: |
print('没有找到该元素') |
return None |
data = self.point.next.data |
print('ID 姓名 成绩') |
print('{} {} {}'.format(data['id'], data['name'], data['grade'])) |
# 信息排序 |
def rank_info(self): |
choice = input('1.成绩排序 2.学号排序：') |
order = input('1.升序 2.降序：') |
if choice == '1': |
item = 'grade' |
elif choice == '2': |
item = 'id' |
else: |
return None |
self.sort(item=item) |
if order == '2': |
temp = self.reverse() |
temp.display_info() |
return None |
self.display_info() |
# 显示信息 |
def display_info(self): |
self.point = self.head |
print('ID 姓名 成绩') |
while self.point.next: |
self.point = self.point.next |
data = self.point.data |
print('{} {} {}'.format(data['id'], data['name'], data['grade'])) |
print('') |
def main(): |
SCS = StudentControlSystem() |
try: |
with open('database.txt', 'r') as f: |
for data in f.readlines(): |
SCS.append(eval(data)) |
except: |
with open('database.txt', 'w') as f: |
pass |
while True: |
SCS.print_menu() |
item = input('请输入你的选择：') |
SCS.user_input(item) |
if __name__ == "__main__": |
main() |
学生成绩管理系统.zip(免费下载)[48 次下载]
