# 15.三数之和

![image-20211229103459272](C:%5CUsers%5CAdnim%5CAppData%5CRoaming%5CTypora%5Ctypora-user-images%5Cimage-20211229103459272.png)「不重复」的本质是什么？我们保持三重循环的大框架不变，

1.不重复的话， 只需要保证：

第二重循环枚举到的元素不小于当前第一重循环枚举到的元素；

第三重循环枚举到的元素不小于当前第二重循环枚举到的元素。

那么肯定是需要进行一次排序


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