diff --git a/docs/notes/Leetcode 题解 - 贪心思想.md b/docs/notes/Leetcode 题解 - 贪心思想.md
index f75bddc9..87669d52 100644
--- a/docs/notes/Leetcode 题解 - 贪心思想.md	
+++ b/docs/notes/Leetcode 题解 - 贪心思想.md	
@@ -106,13 +106,15 @@ public int eraseOverlapIntervals(int[][] intervals) {
 
 ```java
 Arrays.sort(intervals, new Comparator<int[]>() {
-    @Override
-    public int compare(int[] o1, int[] o2) {
-        return o1[1] - o2[1];
-    }
+     @Override
+     public int compare(int[] o1, int[] o2) {
+         return (o1[1] < o2[1]) ? -1 : ((o1[1] == o2[1]) ? 0 : 1);
+     }
 });
 ```
 
+实现 compare() 函数时避免使用 `return o1[1] - o2[1];` 这种减法操作，防止溢出。
+
 # 3. 投飞镖刺破气球
 
 452\. Minimum Number of Arrows to Burst Balloons (Medium)
diff --git a/notes/Leetcode 题解 - 贪心思想.md b/notes/Leetcode 题解 - 贪心思想.md
index f75bddc9..87669d52 100644
--- a/notes/Leetcode 题解 - 贪心思想.md	
+++ b/notes/Leetcode 题解 - 贪心思想.md	
@@ -106,13 +106,15 @@ public int eraseOverlapIntervals(int[][] intervals) {
 
 ```java
 Arrays.sort(intervals, new Comparator<int[]>() {
-    @Override
-    public int compare(int[] o1, int[] o2) {
-        return o1[1] - o2[1];
-    }
+     @Override
+     public int compare(int[] o1, int[] o2) {
+         return (o1[1] < o2[1]) ? -1 : ((o1[1] == o2[1]) ? 0 : 1);
+     }
 });
 ```
 
+实现 compare() 函数时避免使用 `return o1[1] - o2[1];` 这种减法操作，防止溢出。
+
 # 3. 投飞镖刺破气球
 
 452\. Minimum Number of Arrows to Burst Balloons (Medium)