# 分治法思想-判断某个元素是否在列表中

```python
# 子问题，规模为1，len(init_list)=1
def is_in_list(init_list,evl):
    return [False,True][init_list[0]==evl]

def solve(init_list,evl):
    n=len(init_list)#计算问题规模
    print(init_list)
    if n==1:
        return is_in_list(init_list,evl)
    else:
        left_list,right_list=init_list[:n//2],init_list[n//2:]
#         先判断左边，当左边为False时，才判断右边
        res=solve(left_list,evl) or solve(right_list,evl)
        return res

data=[12,3,5,77,4,9,23,56,35,8]
print(solve(data,8))
```

```
[12, 3, 5, 77, 4, 9, 23, 56, 35, 8]
[12, 3, 5, 77, 4]
[12, 3]
[12]
[3]
[5, 77, 4]
[5]
[77, 4]
[77]
[4]
[9, 23, 56, 35, 8]
[9, 23]
[9]
[23]
[56, 35, 8]
[56]
[35, 8]
[35]
[8]
True
```


---

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