diff --git a/src/main/java/com/cool/ling_cha_mount/sliding_windows/Num2831.java b/src/main/java/com/cool/ling_cha_mount/sliding_windows/Num2831.java
index 7846897..5c0af69 100644
--- a/src/main/java/com/cool/ling_cha_mount/sliding_windows/Num2831.java
+++ b/src/main/java/com/cool/ling_cha_mount/sliding_windows/Num2831.java
@@ -48,6 +48,36 @@ public class Num2831 {
         return res;
     }
 
+    /**
+     * @Author Cool
+     * @Date 19:19 2024/10/28
+     * 灵神解法
+     **/
+    public int longestEqualSubarray1(List<Integer> nums, int k) {
+        int n = nums.size();
+        List<Integer>[] posLists = new ArrayList[n + 1];
+        Arrays.setAll(posLists, i -> new ArrayList<>());
+        for (int i = 0; i < n; i++) {
+            int x = nums.get(i);
+            posLists[x].add(i - posLists[x].size());
+        }
+
+        int ans = 0;
+        for (List<Integer> pos : posLists) {
+            if (pos.size() <= ans) {
+                continue; // 无法让 ans 变得更大
+            }
+            int left = 0;
+            for (int right = 0; right < pos.size(); right++) {
+                while (pos.get(right) - pos.get(left) > k) { // 要删除的数太多了
+                    left++;
+                }
+                ans = Math.max(ans, right - left + 1);
+            }
+        }
+        return ans;
+    }
+
     @Test
     public void test() {
         List<Integer> objects = new ArrayList<>();