Details:

Find the unique number

There is an array with some numbers. All numbers are equal except for one. Try to find it!

findUniq([ 1, 1, 1, 2, 1, 1 ]) === 2
findUniq([ 0, 0, 0.55, 0, 0 ]) === 0.55

It’s guaranteed that array contains more than 3 numbers.

The tests contain some very huge arrays, so think about performance.

This is the first kata in series:

1. Find the unique number (this kata)
2. Find the unique string
3. Find The Unique

中文大概含义:

找出最少的一个数字,或者说独一无二的数字

我自己的代码如下:

def find_uniq1(arr):
    counter = collections.Counter(arr)
    count_pair = sorted(counter.items(),key=lambda x:-x[1])
    return count_pair.pop()[0]

第一名代码:

def find_uniq(arr):
    a, b = set(arr)
    return a if arr.count(a) == 1 else b

第四名代码:

def find_uniq2(arr):
    s = set(arr)
    for e in s:
        if arr.count(e) == 1:
            return e

1. 第一名代码有问题,有点投机取巧的感觉,随便写一个[ 0, 0, 0.55, 0, 0,1,1 ]就无法运行~~
2. 第四名代码属于常规写法,最简单的一种.
3. 我的代码使用了collection模块,也很简单.

• 这道题难度系数六级
• 天外有天,人外有人~~