Assert.notEmpty

Assert.notEmpty是一个常见的断言方法，用于确保给定的集合对象不为空。如果集合为空，则会抛出一个IllegalArgumentException异常。该方法通常用于验证方法参数或返回值，以确保它们不包含任何无效或缺失的数据。

以下是Assert.notEmpty方法的示例用法：

public void processList(List<String> items) {
    Assert.notEmpty(items, "List must not be empty");
    // process the list here...
}

在上面的示例中，如果items列表为空，将抛出一个IllegalArgumentException异常，并显示“List must not be empty”消息。这有助于确保代码的正确性和可靠性。

相关问题

Write a function link_to_list that takes in a linked list and returns the sequence as a Python list. You may assume that the input list is shallow; none of the elements is another linked list. Try to find both an iterative and recursive solution for this problem!其中class Link: empty = () def init(self, first, rest=empty): assert rest is Link.empty or isinstance(rest, Link) self.first = first self.rest = rest def repr(self): if self.rest is not Link.empty: rest_repr = ', ' + repr(self.rest) else: rest_repr = '' return 'Link(' + repr(self.first) + rest_repr + ')' def str(self): string = '<' while self.rest is not Link.empty: string += str(self.first) + ' ' self = self.rest return string + str(self.first) + '>'

Sure! Here's an iterative solution for the function link_to_list:

def link_to_list_iter(link):
    result = []
    while link is not Link.empty:
        result.append(link.first)
        link = link.rest
    return result

And here's a recursive solution:

def link_to_list_rec(link):
    if link is Link.empty:
        return []
    else:
        return [link.first] + link_to_list_rec(link.rest)

Both functions take a linked list as input and return it as a Python list. Hope this helps!

修改以下代码：MaxSize=20 #全局变量，假设容量为100 class CSqQueue1: #本例循环队列类 def __init__(self): #构造方法 self.data=[None]*MaxSize #存放队列中元素 self.rear=0 #队头指针 self.count=0 #队中元素个数 self.front = (self.rear - self.count + MaxSize) % MaxSize #队列的基本运算算法 def empty(self): #判断队列是否为空 return self.count==0 def push(self,e): #元素e进队 assert self.count!=MaxSize #检测队满 rear=(self.rear+1) % MaxSize self.data[rear]=e self.count+=1 #元素个数增1 def pop(self): # 出队元素 assert not self.empty() # 检测队空 self.count -= 1 # 元素个数减1 self.front = (self.rear - self.count + MaxSize) % MaxSize # 队头指针循环进1 return self.data[self.front] def gethead(self): # 取队头元素 assert not self.empty() # 检测队空 head = (self.front + 1) % MaxSize # 求队头元素的位置 return self.data[head] def size(self): # 返回队中元素个数 return ((self.rear - self.front + MaxSize) % MaxSize) #主程序 if __name__ == '__main__': st=CSqQueue1() st.push(7) st.push(5) st.push(10) st.push(3) print() print("队头元素: %d" % (st.gethead())) print(" 队列元素个数:%d" % (st.size())) print(" 出队元素:%d" % (st.pop())) print(" 队列元素个数:%d" % (st.size())) print()

MaxSize应该是100，而不是20。另外，队头指针的计算公式也需要修改为(self.rear - self.count + MaxSize) % MaxSize。修改后的代码如下：

MaxSize=100                      	#全局变量，假设容量为100
class CSqQueue1:      		#本例循环队列类
    def __init__(self):               	#构造方法
        self.data=[None]*MaxSize        	#存放队列中元素
        self.rear=0                    	#队头指针
        self.count=0			#队中元素个数
        self.front = (self.rear - self.count + MaxSize) % MaxSize #队列的基本运算算法
    def empty(self):				#判断队列是否为空
        return self.count==0
    def push(self,e):				#元素e进队
        assert self.count!=MaxSize        	#检测队满
        rear=(self.rear+1) % MaxSize
        self.data[rear]=e
        self.count+=1			      	#元素个数增1
    def pop(self):  # 出队元素
        assert not self.empty()  # 检测队空
        self.count -= 1  # 元素个数减1
        self.front = (self.rear - self.count + MaxSize) % MaxSize # 队头指针循环进1
        return self.data[self.front]
    def gethead(self):  # 取队头元素
        assert not self.empty()  # 检测队空
        head = (self.front + 1) % MaxSize  # 求队头元素的位置
        return self.data[head]
    def size(self):  # 返回队中元素个数
        return ((self.rear - self.front + MaxSize) % MaxSize)
#主程序
if __name__ == '__main__':
    st=CSqQueue1()
    st.push(7)
    st.push(5)
    st.push(10)
    st.push(3)
    print()
    print("队头元素: %d" % (st.gethead()))
    print(" 队列元素个数:%d" % (st.size()))
    print(" 出队元素:%d" % (st.pop()))
    print(" 队列元素个数:%d" % (st.size()))
    print()