532. K-diff Pairs in an Array, k-diffpairs

532. K-diff Pairs in an Array, k-diffpairs

From:

Http://bookshadow.com/weblog/2017/03/05/leetcode-k-diff-pairs-in-an-array/

 

Summary:

1. Counter usage in the container class

Http://www.cnblogs.com/shawnChi/p/6484591.html

2. When k = 0, if the value corresponding to the key is greater than 1, The list contains at least two Key values, sum + 1;
3. When k> 0, the value corresponding to the key must be greater than 0. That is, when n is in the list, n + k can also be in the list to sum + 1.