add sort

Author: Ehco1996

docs/12_基本排序算法/basic_sort.py

@@ -50,7 +50,7 @@ def insertion_sort(seq):
         # 找到这个值的合适位置，使得前边的数组有序 [0,i] 有序
         pos = i
         while pos > 0 and value < seq[pos-1]:
-            seq[pos] = seq[pos-1]  # 如果前边的元素比它大，就让它一直前移
+            seq[pos] = seq[pos-1]  # 如果前边的元素比它大，就让它一直后移
             pos -= 1
         seq[pos] = value    # 找到了合适的位置赋值就好
         print(seq)

ehco/hashtable/hashtable_adt.py

@@ -1,30 +1,8 @@
-class Array(object):
+from ehco.array_list.array_and_list import Array
 
-    def __init__(self, size=32, init=None):
-        self._size = size
-        self._items = [init] * 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):
+class Slot:
     """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
@@ -35,7 +13,7 @@ def __init__(self, key, value):
         self.key, self.value = key, value
 
 
-class HashTable(object):
+class HashTable:
 
     # 没有被使用过的
     UNUSED = None
@@ -48,7 +26,6 @@ def __init__(self):
 
     @property
     def _load_factor(self):
-        # load factor 超过0.8的时候重新分配
         return self.length / float(len(self._table))
 
     def __len__(self):
@@ -134,18 +111,18 @@ def __iter__(self):
 def test_hash_table():
     h = HashTable()
 
-    h.add('a', 0)
-    h.add('b', 1)
-    h.add('c', 2)
+    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
+    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']
+    h.remove("a")
+    assert h.get("a") is None
+    assert sorted(list(h)) == ["b", "c"]
 
     n = 50
     for i in range(n):

ehco/quick_sort/sort.py

@@ -0,0 +1,59 @@
+def bubble_sort(array):
+    "O(n2)"
+    lens = len(array) - 1
+    for i in range(lens):
+        for j in range(lens - i):
+            if array[j] > array[j + 1]:
+                array[j], array[j + 1] = array[j + 1], array[j]
+    return array
+
+
+def select_sort(array):
+    "O(n2)"
+    lens = len(array)
+    for i in range(lens):
+        min_idx = i
+        for j in range(i + 1, lens):
+            if array[j] < array[min_idx]:
+                min_idx = j
+        if min_idx != i:
+            array[i], array[min_idx] = array[min_idx], array[i]
+    return array
+
+
+def insert_sort(array):
+    "O(n2)"
+    lens = len(array)
+    for i in range(1, lens):
+        val = array[i]
+        pos = i
+        while pos > 0 and val < array[pos - 1]:
+            # 把大的值往后移动
+            array[pos] = array[pos - 1]
+            pos -= 1
+        array[pos] = val
+    return array
+
+
+def quick_sort(array):
+    size = len(array)
+    if not array or size < 2:
+        return array
+    pivot_idx = 0
+    pivot = array[pivot_idx]
+    less_part = [array[i] for i in range(size) if array[i] <= pivot and pivot_idx != i]
+    great_part = [array[i] for i in range(size) if array[i] > pivot and pivot_idx != i]
+    return quick_sort(less_part) + [pivot] + quick_sort(great_part)
+
+
+def test_sort():
+    import random
+
+    seq = list(range(10))
+    random.shuffle(seq)
+
+    assert bubble_sort(seq) == sorted(seq)
+    assert select_sort(seq) == sorted(seq)
+    assert insert_sort(seq) == sorted(seq)
+    assert quick_sort(seq) == sorted(seq)
+