Create psf.py

honglongwei · honglongwei · commit b00b0898301f · 2016-04-21T14:38:24.000+08:00
八大排序算法的 Python 实现
diff --git a/psf.py b/psf.py
@@ -0,0 +1,139 @@
+1、插入排序  
+def insert_sort(lists):  
+    # 插入排序  
+    count = len(lists)  
+    for i in range(1, count):  
+        key = lists[i]  
+        j = i - 1  
+        while j >= 0:  
+            if lists[j] > key:  
+                lists[j + 1] = lists[j]  
+                lists[j] = key  
+            j -= 1  
+    return lists  
+   
+2、希尔排序  
+def shell_sort(lists):  
+    # 希尔排序  
+    count = len(lists)  
+    step = 2  
+    group = count / step  
+    while group > 0:  
+        for i in range(0, group):  
+            j = i + group  
+            while j < count:  
+                k = j - group  
+                key = lists[j]  
+                while k >= 0:  
+                    if lists[k] > key:  
+                        lists[k + group] = lists[k]  
+                        lists[k] = key  
+                    k -= group  
+                j += group  
+        group /= step  
+    return lists  
+   
+3、冒泡排序  
+def bubble_sort(lists):  
+    # 冒泡排序  
+    count = len(lists)  
+    for i in range(0, count):  
+        for j in range(i + 1, count):  
+            if lists[i] > lists[j]:  
+                lists[i], lists[j] = lists[j], lists[i]  
+    return lists  
+   
+4、快速排序  
+def quick_sort(lists, left, right):  
+    # 快速排序  
+    if left >= right:  
+        return lists  
+    key = lists[left]  
+    low = left  
+    high = right  
+    while left < right:  
+        while left < right and lists[right] >= key:  
+            right -= 1  
+        lists[left] = lists[right]  
+        while left < right and lists[left] <= key:  
+            left += 1  
+        lists[right] = lists[left]  
+    lists[right] = key  
+    quick_sort(lists, low, left - 1)  
+    quick_sort(lists, left + 1, high)  
+    return lists  
+   
+5、直接选择排序  
+def select_sort(lists):  
+    # 选择排序  
+    count = len(lists)  
+    for i in range(0, count):  
+        min = i  
+        for j in range(i + 1, count):  
+            if lists[min] > lists[j]:  
+                min = j  
+        lists[min], lists[i] = lists[i], lists[min]  
+    return lists  
+   
+6、堆排序  
+# 调整堆  
+def adjust_heap(lists, i, size):  
+    lchild = 2 * i + 1  
+    rchild = 2 * i + 2  
+    max = i  
+    if i < size / 2:  
+        if lchild < size and lists[lchild] > lists[max]:  
+            max = lchild  
+        if rchild < size and lists[rchild] > lists[max]:  
+            max = rchild  
+        if max != i:  
+            lists[max], lists[i] = lists[i], lists[max]  
+            adjust_heap(lists, max, size)  
+# 创建堆  
+def build_heap(lists, size):  
+    for i in range(0, (size/2))[::-1]:  
+        adjust_heap(lists, i, size)  
+# 堆排序  
+def heap_sort(lists):  
+    size = len(lists)  
+    build_heap(lists, size)  
+    for i in range(0, size)[::-1]:  
+        lists[0], lists[i] = lists[i], lists[0]  
+        adjust_heap(lists, 0, i)  
+   
+7、归并排序  
+def merge(left, right):  
+    i, j = 0, 0  
+    result = []  
+    while i < len(left) and j < len(right):  
+        if left[i] <= right[j]:  
+            result.append(left[i])  
+            i += 1  
+        else:  
+            result.append(right[j])  
+            j += 1  
+    result += left[i:]  
+    result += right[j:]  
+    return result  
+def merge_sort(lists):  
+    # 归并排序  
+    if len(lists) <= 1:  
+        return lists  
+    num = len(lists) / 2  
+    left = merge_sort(lists[:num])  
+    right = merge_sort(lists[num:])  
+    return merge(left, right)  
+   
+8、基数排序  
+import math  
+def radix_sort(lists, radix=10):  
+    k = int(math.ceil(math.log(max(lists), radix)))  
+    bucket = [[] for i in range(radix)]  
+    for i in range(1, k+1):  
+        for j in lists:  
+            bucket[j/(radix**(i-1)) % (radix**i)].append(j)  
+        del lists[:]  
+        for z in bucket:  
+            lists += z  
+            del z[:]  
+    return lists
