1.2 顺序表python（25段代码）
<h1>顺序表的构建</h1>
<pre><code class="language-python">class Seq:
def __init__(self, size=20):
&quot;&quot;&quot;
初始化Seq类的实例
:param size: 序列的初始大小，默认为20
&quot;&quot;&quot;
self.size = size # 序列的大小
self.curNum = 0 # 当前已存储的元素数量
self.element = [None] * size # 初始化一个固定大小的列表，用于存储元素</code></pre>
<h1>顺序表的操作</h1>
<h1>辅助操作</h1>
<h2>【格式化输出】</h2>
<p>其中append方法，在后文会具体实现。</p>
<p>简单的：</p>
<pre><code class="language-python">class Seq:
def show(self):
for i in range(self.curNum):
print(self.element[i], end=&#039; &#039;)</code></pre>
<p>高级的：</p>
<pre><code class="language-python">class Seq:
def __str__(self):
s = &#039;&#039;
for i in range(self.curNum):
s += str(self.element[i]) + &#039; &#039;
return s</code></pre>
<p>其中<strong>str</strong>是python对象的特殊方法，当调用print的时候，自动调用<strong>str</strong>的返回值。</p>
<h2>【扩容】</h2>
<p>当超出容量时，可以报错，也可以选择扩容（其中length方法在后文会实现）：</p>
<pre><code class="language-python">class Seq:
def grow(self, k=2):
self.size *= k
self.element += [None]*(self.size*(k-1))</code></pre>
<p> </p>
<h2>【判断是不是空】</h2>
<pre><code class="language-python">class Seq:
def isempty(self):
return self.curNum == 0</code></pre>
<p> </p>
<h2>【判断是不是满】</h2>
<pre><code class="language-python">class Seq:
def isfull(self):
return self.curNum == self.size</code></pre>
<p> </p>
<h1>增加元素</h1>
<h2>【添加】</h2>
<p>方式1：当容量满了，扩容</p>
<pre><code class="language-python">class Seq:
def append(self, m):
if self.isfull():
self.grow()
self.element[self.curNum] = m
self.curNum += 1</code></pre>
<p>方式2：当容量满了，不执行，方法返回1，表示操作失败，否则返回0</p>
<pre><code class="language-python">class Seq:
def append(self, m):
if self.isfull():
return 1
self.element[self.curNum] = m
self.curNum += 1
return 0</code></pre>
<p> </p>
<h2>【插入】</h2>
<p>方式1：当容量满了，扩容</p>
<pre><code class="language-python">class Seq:
def insert(self, i, m):
if i &lt; 0 or i &gt; self.curNum:
return 1
if self.isfull():
print(…)
self.grow()
for j in range(self.curNum, i, -1):
self.element[j] = self.element[j-1]
self.element[i] = m
self.curNum += 1</code></pre>
<p>方式2：当容量满了，不执行，方法返回1，表示操作失败，否则返回0</p>
<pre><code class="language-python">class Seq:
def insert(self, i, m):
if i &lt; 0 or i &gt; self.curNum:
return 1
if self.isfull():
return 1
for j in range(self.curNum, i, -1):
self.element[j] = self.element[j-1]
self.element[i] = m
self.curNum += 1
return 0
</code></pre>
<p> </p>
<h2>【拼接】</h2>
<p>其中append在前文已经实现：</p>
<p>方式1：拼接时，通过grow方式增加容量</p>
<pre><code class="language-python">class Seq:
def extend(self, other):
while (self.curNum+other.curNum) &gt; self.size:
self.grow()
for i in range(other.curNum):
self.append(other.element[i])
</code></pre>
<p>方式2：拼接时，直接合并两者容量：</p>
<pre><code class="language-python">class Seq:
def extend(self, other):
self.size += other.size
self.element += [None]*other.size
for i in range(other.curNum):
self.append(other.element[i])
</code></pre>
<p> </p>
<h1>删除元素</h1>
<h2>【弹出一个元素】</h2>
<pre><code class="language-python">class Seq:
def pop(self):
if self.isempty():
return 1
res = self.element[self.curNum-1]
self.element[self.curNum - 1] = None
self.curNum -= 1
return res</code></pre>
<p> </p>
<h2>【删除第i个】</h2>
<pre><code class="language-python">class Seq:
def popi(self, i):
if i &lt; 0 or i &gt;= self.curNum:
return 1
for j in range(i, self.curNum-1):
self.element[j] = self.element[j+1]
self.element[self.curNum-1] = None
self.curNum -= 1</code></pre>
<p> </p>
<h2>【删除n这个值】</h2>
<p>其中，popi在前文已经实现</p>
<pre><code class="language-python">class Seq:
def remove(self, n):
for i in range(self.curNum-1, -1, -1):
if self.element[i] == n:
self.popi(i)
</code></pre>
<p> </p>
<h2>【清空】</h2>
<pre><code class="language-python">class Seq:
def clear(self):
self.curNum = 0
self.element = [None] * self.size</code></pre>
<p> </p>
<h2>【删除一段】</h2>
<pre><code class="language-python">class Seq:
def cut(self, start=0, end=None):
# 不用判断错误，因为在popi中已经处理
if end is None:
end = self.curNum
for k in range(end-1, start-1, -1):
self.popi(k)</code></pre>
<p> </p>
<h1>修改</h1>
<h2>【修改第i个值】</h2>
<pre><code class="language-python">class Seq:
def set(self, i, x):
if i &lt; 0 or i &gt;= self.curNum:
return 1
self.element[i] = x</code></pre>
<p> </p>
<h2>【替换x为y】</h2>
<pre><code class="language-python">class Seq:
def replace(self, x, y):
for i in range(self.curNum):
if self.element[i] == x:
self.element[i] = y
</code></pre>
<p> </p>
<h2>【翻转】</h2>
<pre><code class="language-python">class Seq:
def reverse(self):
for i in range(self.curNum//2):
j = self.curNum - 1 - i
self.element[i], self.element[j] = self.element[j], self.element[i]
</code></pre>
<h1>查询</h1>
<h2>【获取长度】</h2>
<pre><code class="language-python">class Seq:
def length(self):
return self.curNum</code></pre>
<h2>【获取最大值/最小值】</h2>
<pre><code class="language-python">class Seq:
def max(self):
if self.isempty():
return None
res = self.element[0]
for i in range(1, self.curNum):
if self.element[i] &gt; res:
res = self.element[i]
return res</code></pre>
<p>最小值略。</p>
<p> </p>
<h2>【判断某个值在不在里面】</h2>
<pre><code class="language-python">class Seq:
def has(self, k):
for i in range(self.curNum):
if self.element[i] == k:
return True
return False</code></pre>
<p> </p>
<h2>【获取某个位置的值】</h2>
<pre><code class="language-python">class Seq:
def get(self, i):
if i &lt; 0 or i &gt;= self.curNum:
return 1
return self.element[i]</code></pre>
<p> </p>
<h2>【获取某个值的位置】</h2>
<pre><code class="language-python">class Seq:
def index(self, x):
for i in range(self.curNum):
if self.element[i] == x:
return i
return -1
</code></pre>