已知有20个学生记录（包括学号，姓名，成绩等） 设计三个查找算法，分别实现按学号、姓名、成绩的顺序查找； 菜单选择查找方式；

可以使用以下三种查找算法实现按学号、姓名、成绩的顺序查找：

1. 顺序查找

顺序查找（Sequential Search）是一种简单的查找算法，它从数据的起始位置开始依次比较每个元素，直到找到目标元素或搜索到数据的末尾为止。

实现按学号顺序查找的代码示例：

def search_by_id(students, target_id):
    for student in students:
        if student['id'] == target_id:
            return student
    return None

实现按姓名顺序查找的代码示例：

def search_by_name(students, target_name):
    for student in students:
        if student['name'] == target_name:
            return student
    return None

实现按成绩顺序查找的代码示例：

def search_by_score(students, target_score):
    for student in students:
        if student['score'] == target_score:
            return student
    return None

2. 二分查找

二分查找（Binary Search）是一种高效的查找算法，它要求待查找的数据必须有序，每次查找可以将数据范围缩小一半。

实现按学号顺序查找的代码示例：

def binary_search_by_id(students, target_id):
    left = 0
    right = len(students) - 1
    while left <= right:
        mid = (left + right) // 2
        if students[mid]['id'] == target_id:
            return students[mid]
        elif students[mid]['id'] < target_id:
            left = mid + 1
        else:
            right = mid - 1
    return None

实现按姓名顺序查找的代码示例：

def binary_search_by_name(students, target_name):
    left = 0
    right = len(students) - 1
    while left <= right:
        mid = (left + right) // 2
        if students[mid]['name'] == target_name:
            return students[mid]
        elif students[mid]['name'] < target_name:
            left = mid + 1
        else:
            right = mid - 1
    return None

实现按成绩顺序查找的代码示例：

def binary_search_by_score(students, target_score):
    left = 0
    right = len(students) - 1
    while left <= right:
        mid = (left + right) // 2
        if students[mid]['score'] == target_score:
            return students[mid]
        elif students[mid]['score'] < target_score:
            left = mid + 1
        else:
            right = mid - 1
    return None

3. 哈希查找

哈希查找（Hash Search）是一种基于哈希表的查找算法，它利用哈希函数将查找的关键字映射到哈希表中的一个位置，并在该位置查找目标元素。

实现按学号顺序查找的代码示例：

def hash_search_by_id(students, target_id):
    hash_table = {}
    for student in students:
        hash_table[student['id']] = student
    return hash_table.get(target_id)

实现按姓名顺序查找的代码示例：

def hash_search_by_name(students, target_name):
    hash_table = {}
    for student in students:
        hash_table[student['name']] = student
    return hash_table.get(target_name)

实现按成绩顺序查找的代码示例：

def hash_search_by_score(students, target_score):
    hash_table = {}
    for student in students:
        hash_table[student['score']] = student
    return hash_table.get(target_score)

可以使用以下代码实现菜单选择查找方式：

students = [{'id': 1, 'name': '张三', 'score': 90},
            {'id': 2, 'name': '李四', 'score': 80},
            {'id': 3, 'name': '王五', 'score': 70},
            {'id': 4, 'name': '赵六', 'score': 60},
            {'id': 5, 'name': '钱七', 'score': 50},
            {'id': 6, 'name': '孙八', 'score': 40},
            {'id': 7, 'name': '周九', 'score': 30},
            {'id': 8, 'name': '吴十', 'score': 20},
            {'id': 9, 'name': '郑一', 'score': 10},
            {'id': 10, 'name': '刘二', 'score': 100},
            {'id': 11, 'name': '陈三', 'score': 95},
            {'id': 12, 'name': '黄四', 'score': 85},
            {'id': 13, 'name': '林五', 'score': 75},
            {'id': 14, 'name': '周六', 'score': 65},
            {'id': 15, 'name': '刘七', 'score': 55},
            {'id': 16, 'name': '杨八', 'score': 45},
            {'id': 17, 'name': '吴九', 'score': 35},
            {'id': 18, 'name': '郑十', 'score': 25},
            {'id': 19, 'name': '孙一', 'score': 15},
            {'id': 20, 'name': '张二', 'score': 5}]

while True:
    print('请选择查找方式：')
    print('1. 按学号查找')
    print('2. 按姓名查找')
    print('3. 按成绩查找')
    print('4. 退出程序')
    choice = input('请输入选项：')
    if choice == '1':
        target_id = int(input('请输入要查找的学号：'))
        result = binary_search_by_id(students, target_id)
        if result:
            print(result)
        else:
            print('未找到该学生记录')
    elif choice == '2':
        target_name = input('请输入要查找的姓名：')
        result = binary_search_by_name(students, target_name)
        if result:
            print(result)
        else:
            print('未找到该学生记录')
    elif choice == '3':
        target_score = int(input('请输入要查找的成绩：'))
        result = binary_search_by_score(students, target_score)
        if result:
            print(result)
        else:
            print('未找到该学生记录')
    elif choice == '4':
        break
    else:
        print('输入有误，请重新输入')