add credit

fishercoder1534 · fishercoder1534 · commit c82519f87f1b · 2017-04-30T13:11:55.000-07:00
diff --git a/src/main/java/com/stevesun/solutions/_560.java b/src/main/java/com/stevesun/solutions/_560.java
@@ -17,6 +17,7 @@
  */
 public class _560 {
 
+    //credit: https://discuss.leetcode.com/topic/87850/java-solution-presum-hashmap
     public int subarraySum(int[] nums, int k) {
         Map<Integer, Integer> preSum = new HashMap();
         int sum = 0;
