Merge pull request #63 from jerryderry/master

bubble sort, insertion sort and selection sort in python

python/11_sorts/sorts.py

@@ -0,0 +1,95 @@
+"""
+    Bubble sort, insertion sort and selection sort
+    冒泡排序、插入排序、选择排序
+
+    Author: Wenru
+"""
+
+from typing import List
+
+# 冒泡排序
+def bubble_sort(a: List[int]):
+    if len(a) <= 1: return
+    
+    made_swap = False
+    for i in range(len(a)):
+        for j in range(len(a) - i - 1):
+            if a[j] > a[j+1]:
+                a[j], a[j+1] = a[j+1], a[j]
+                made_swap = True
+        if not made_swap: break
+
+# 插入排序
+def insertion_sort(a: List[int]):
+    if len(a) <= 1: return
+    
+    for i in range(1, len(a)):
+        value = a[i]
+        j = i - 1
+        while j >= 0 and a[j] > value:
+            a[j+1] = a[j]
+            j -= 1
+        a[j+1] = value
+
+# 选择排序
+def selection_sort(a: List[int]):
+    if len(a) <= 1: return
+    
+    for i in range(len(a)):
+        min_index = i
+        min_val = a[i]
+        for j in range(i, len(a)):
+            if a[j] < min_val:
+                min_val = a[j]
+                min_index = j
+        a[i], a[min_index] = a[min_index], a[i]
+
+
+if __name__ == "__main__":
+    array = [1, 1, 1, 1]
+    bubble_sort(array)
+    print(array)
+
+    array = [1, 2, 3, 4]
+    bubble_sort(array)
+    print(array)
+
+    array = [4, 3, 2, 1]
+    bubble_sort(array)
+    print(array)
+
+    array = [5, 6, -1, 4, 2, 8, 10, 7, 6]
+    bubble_sort(array)
+    print(array)
+
+    array = [1, 1, 1, 1]
+    insertion_sort(array)
+    print(array)
+
+    array = [1, 2, 3, 4]
+    insertion_sort(array)
+    print(array)
+
+    array = [4, 3, 2, 1]
+    insertion_sort(array)
+    print(array)
+
+    array = [5, 6, -1, 4, 2, 8, 10, 7, 6]
+    insertion_sort(array)
+    print(array)
+
+    array = [1, 1, 1, 1]
+    selection_sort(array)
+    print(array)
+
+    array = [1, 2, 3, 4]
+    selection_sort(array)
+    print(array)
+
+    array = [4, 3, 2, 1]
+    selection_sort(array)
+    print(array)
+
+    array = [5, 6, -1, 4, 2, 8, 10, 7, 6]
+    selection_sort(array)
+    print(array)