python经典算法示例
时间: 2024-10-10 19:01:52 浏览: 3
Python是一门广泛应用的编程语言,支持许多经典的算法实现。以下是几个常见的Python算法示例:
1. **排序算法** - Python内置了`sorted()`函数可以对列表进行排序,如快速排序、归并排序等。例如,快速排序的简单实现:
```python
def quicksort(arr):
if len(arr) <= 1:
return arr
pivot = arr[len(arr) // 2]
left = [x for x in arr if x < pivot]
middle = [x for x in arr if x == pivot]
right = [x for x in arr if x > pivot]
return quicksort(left) + middle + quicksort(right)
arr = [3,6,8,10,1,2,1]
print(quicksort(arr))
```
2. **搜索算法** - 如线性查找(遍历列表寻找目标值):
```python
def linear_search(lst, target):
for i in range(len(lst)):
if lst[i] == target:
return i
return None
lst = [1, 4, 7, 9, 11]
target = 7
result = linear_search(lst, target)
if result is not None:
print(f"元素在索引 {result}")
else:
print("未找到")
```
3. **递归算法** - 如斐波那契数列:
```python
def fibonacci(n):
if n <= 0:
return 0
elif n == 1:
return 1
else:
return fibonacci(n-1) + fibonacci(n-2)
n = 10
fib = fibonacci(n)
print(f"第{n}项斐波那契数是: {fib}")
```