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0_课程简介之笨方法学算法/why_and_how_to_learn/index.html

@@ -104,6 +104,16 @@
     <a class="" href="../../7_哈希表/hashtable/">哈希表</a>
 	    </li>
 
+            <li class="toctree-l1">
+		
+    <a class="" href="../../8_字典/dict/">字典</a>
+	    </li>
+          
+            <li class="toctree-l1">
+		
+    <a class="" href="../../9_集合/set/">集合</a>
+	    </li>
+          
         </ul>
       </div>
       &nbsp;

1_抽象数据类型和面向对象编程/ADT_OOP/index.html

@@ -113,6 +113,16 @@
     <a class="" href="../../7_哈希表/hashtable/">哈希表</a>
 	    </li>
 
+            <li class="toctree-l1">
+		
+    <a class="" href="../../8_字典/dict/">字典</a>
+	    </li>
+          
+            <li class="toctree-l1">
+		
+    <a class="" href="../../9_集合/set/">集合</a>
+	    </li>
+          
         </ul>
       </div>
       &nbsp;

2_数组和列表/array_and_list/index.html

@@ -113,6 +113,16 @@
     <a class="" href="../../7_哈希表/hashtable/">哈希表</a>
 	    </li>
 
+            <li class="toctree-l1">
+		
+    <a class="" href="../../8_字典/dict/">字典</a>
+	    </li>
+          
+            <li class="toctree-l1">
+		
+    <a class="" href="../../9_集合/set/">集合</a>
+	    </li>
+          
         </ul>
       </div>
       &nbsp;

3_链表/linked_list/index.html

@@ -110,6 +110,16 @@
     <a class="" href="../../7_哈希表/hashtable/">哈希表</a>
 	    </li>
 
+            <li class="toctree-l1">
+		
+    <a class="" href="../../8_字典/dict/">字典</a>
+	    </li>
+          
+            <li class="toctree-l1">
+		
+    <a class="" href="../../9_集合/set/">集合</a>
+	    </li>
+          
         </ul>
       </div>
       &nbsp;

404.html

@@ -85,6 +85,16 @@
     <a class="" href="/7_哈希表/hashtable/">哈希表</a>
 	    </li>
 
+            <li class="toctree-l1">
+		
+    <a class="" href="/8_字典/dict/">字典</a>
+	    </li>
+          
+            <li class="toctree-l1">
+		
+    <a class="" href="/9_集合/set/">集合</a>
+	    </li>
+          
         </ul>
       </div>
       &nbsp;

4_队列/queue/index.html

@@ -110,6 +110,16 @@
     <a class="" href="../../7_哈希表/hashtable/">哈希表</a>
 	    </li>
 
+            <li class="toctree-l1">
+		
+    <a class="" href="../../8_字典/dict/">字典</a>
+	    </li>
+          
+            <li class="toctree-l1">
+		
+    <a class="" href="../../9_集合/set/">集合</a>
+	    </li>
+          
         </ul>
       </div>
       &nbsp;

5_栈/stack/index.html

@@ -107,6 +107,16 @@
     <a class="" href="../../7_哈希表/hashtable/">哈希表</a>
 	    </li>
 
+            <li class="toctree-l1">
+		
+    <a class="" href="../../8_字典/dict/">字典</a>
+	    </li>
+          
+            <li class="toctree-l1">
+		
+    <a class="" href="../../9_集合/set/">集合</a>
+	    </li>
+          
         </ul>
       </div>
       &nbsp;

6_算法分析/big_o/index.html

@@ -122,6 +122,16 @@
     <a class="" href="../../7_哈希表/hashtable/">哈希表</a>
 	    </li>
 
+            <li class="toctree-l1">
+		
+    <a class="" href="../../8_字典/dict/">字典</a>
+	    </li>
+          
+            <li class="toctree-l1">
+		
+    <a class="" href="../../9_集合/set/">集合</a>
+	    </li>
+          
         </ul>
       </div>
       &nbsp;

7_哈希表/hashtable.py

@@ -0,0 +1,166 @@
+# -*- coding: utf-8 -*-
+
+# 从数组和列表章复制的代码
+
+
+class Array(object):
+
+    def __init__(self, size=32):
+        self._size = size
+        self._items = [None] * size
+
+    def __getitem__(self, index):
+        return self._items[index]
+
+    def __setitem__(self, index, value):
+        self._items[index] = value
+
+    def __len__(self):
+        return self._size
+
+    def clear(self, value=None):
+        for i in range(self._items):
+            self._items[i] = value
+
+    def __iter__(self):
+        for item in self._items:
+            yield item
+
+
+class Slot(object):
+    """定义一个 hash 表 数组的槽
+    注意，一个槽有三种状态，看你能否想明白。相比链接法解决冲突，二次探查法删除一个 key 的操作稍微复杂。
+    1.从未使用 HashMap.UNUSED。此槽没有被使用和冲突过，查找时只要找到 UNUSED 就不用再继续探查了
+    2.使用过但是 remove 了，此时是 HashMap.EMPTY，该探查点后边的元素扔可能是有key
+    3.槽正在使用 Slot 节点
+    """
+
+    def __init__(self, key, value):
+        self.key, self.value = key, value
+
+
+class HashTable(object):
+
+    UNUSED = None    # 没被使用过的槽，作为该类变量的一个单例，下边都是is 判断
+    EMPTY = Slot(None, None)     # 使用过但是被删除的槽
+
+    def __init__(self):
+        self._table = Array(7)
+        self.length = 0
+
+    @property
+    def _load_factor(self):
+        # load factor 超过 2/3 就重新分配空间
+        return self.length / float(len(self._table))
+
+    def __len__(self):
+        return self.length
+
+    def _hash1(self, key):
+        """ 计算key的hash值"""
+        return abs(hash(key)) % len(self._table)
+
+    def _find_slot(self, key, for_insert=False):
+        """_find_slot
+
+        :param key:
+        :param for_insert: 是否插入，还是仅仅查询
+        :return:  slot index or None
+        """
+        index = self._hash1(key)
+        base_index = index
+        hash_times = 1
+        _len = len(self._table)
+
+        if not for_insert:  # 查找是否存在 key
+            while self._table[index] is not HashTable.UNUSED:
+                if self._table[index] is HashTable.EMPTY:
+                    index = (index + hash_times * hash_times) % _len    # 一个简单的二次方探查
+                    continue
+                elif self._table[index].key == key:
+                    return index
+                index = (index + hash_times * hash_times) % _len
+                hash_times += 1
+            return None
+        else:
+            while not self._slot_can_insert(index):  # 循环直到找到一个可以插入的槽
+                index = (index + hash_times * hash_times) % _len
+                hash_times += 1
+            return index
+
+    def _slot_can_insert(self, index):
+        return (self._table[index] is HashTable.EMPTY or self._table[index] is HashTable.UNUSED)
+
+    def __contains__(self, key):   # in operator
+        index = self._find_slot(key, for_insert=False)
+        return index is not None
+
+    def add(self, key, value):
+        if key in self:    # key 相同值不一样的时候，用新的值
+            index = self._find_slot(key, for_insert=False)
+            self._table[index].value = value
+            return False
+        else:
+            index = self._find_slot(key, for_insert=True)
+            self._table[index] = Slot(key, value)
+            self.length += 1
+            if self._load_factor >= 0.8:    # 注意超过了 阈值 rehashing
+                self._rehash()
+            return True
+
+    def _rehash(self):
+        old_table = self._table
+        newsize = len(self._table) * 2 + 1   # 扩大 2*n + 1
+        self._table = Array(newsize)
+
+        self.length = 0
+
+        for slot in old_table:
+            if slot is not HashTable.UNUSED and slot is not HashTable.EMPTY:
+                index = self._find_slot(slot.key, for_insert=True)
+                self._table[index] = slot
+                self.length += 1
+
+    def get(self, key, default=None):
+        index = self._find_slot(key, for_insert=False)
+        if index is None:
+            return default
+        else:
+            return self._table[index].value
+
+    def remove(self, key):
+        assert key in self, 'keyerror'
+        index = self._find_slot(key, for_insert=False)
+        value = self._table[index].value
+        self.length -= 1
+        self._table[index] = HashTable.EMPTY
+        return value
+
+    def __iter__(self):
+        for slot in self._table:
+            if slot not in (HashTable.EMPTY, HashTable.UNUSED):
+                yield slot.key   # 和 python dict 一样，默认遍历 key，需要value 的话写个 items() 方法
+
+
+def test_hash_table():
+    h = HashTable()
+    h.add('a', 0)
+    h.add('b', 1)
+    h.add('c', 2)
+
+    assert len(h) == 3
+    assert h.get('a') == 0
+    assert h.get('b') == 1
+    assert h.get('hehe') is None
+
+    h.remove('a')
+    assert h.get('a') is None
+
+    assert sorted(list(h)) == ['b', 'c']
+
+    # 50 超过了 HashTable 的原始 size，我们测试下是否 reshah 操作能正确工作
+    for i in range(50):
+        h.add(i, i)
+
+    for i in range(50):
+        assert h.get(i) == i