Recca Chao 的 gitHub page

推廣網站開發,包含 Laravel 和 Kotlin 後端撰寫、自動化測試、讀書心得等。Taiwan Kotlin User Group 管理員。

View on GitHub

Hi, here's your problem today. This problem was recently asked by Facebook:

Given a list of numbers, where every number shows up twice except for one number, find that one number.


Input: [4, 3, 2, 4, 1, 3, 2]
Output: 1

Here's the function signature:

def singleNumber(nums):
  # Fill this in.

print singleNumber([4, 3, 2, 4, 1, 3, 2])
# 1

Challenge: Find a way to do this using O(1) memory.