diff --git a/src/main/java/git/snippet/heap/Code_DistanceLessK.java b/src/main/java/git/snippet/heap/Code_DistanceLessK.java
index 5575379460179dc6e652fd7ea4af744c1016f6b1..c4f943ffa7e4423dda6d6b8653fa80163065a620 100644
--- a/src/main/java/git/snippet/heap/Code_DistanceLessK.java
+++ b/src/main/java/git/snippet/heap/Code_DistanceLessK.java
@@ -1,6 +1,5 @@
 package git.snippet.heap;
 
-import java.util.Arrays;
 import java.util.PriorityQueue;
 
 // 笔记：https://www.cnblogs.com/greyzeng/p/16933830.html
@@ -24,102 +23,4 @@ public class Code_DistanceLessK {
             arr[index++] = heap.poll();
         }
     }
-
-    // for test
-    public static void comparator(int[] arr, int k) {
-        Arrays.sort(arr);
-    }
-
-    // for test
-    public static int[] randomArrayNoMoveMoreK(int maxSize, int maxValue, int K) {
-        int[] arr = new int[(int) ((maxSize + 1) * Math.random())];
-        for (int i = 0; i < arr.length; i++) {
-            arr[i] = (int) ((maxValue + 1) * Math.random()) - (int) (maxValue * Math.random());
-        }
-        // 先排个序
-        Arrays.sort(arr);
-        // 然后开始随意交换，但是保证每个数距离不超过K
-        // swap[i] == true, 表示i位置已经参与过交换
-        // swap[i] == false, 表示i位置没有参与过交换
-        boolean[] isSwap = new boolean[arr.length];
-        for (int i = 0; i < arr.length; i++) {
-            int j = Math.min(i + (int) (Math.random() * (K + 1)), arr.length - 1);
-            if (!isSwap[i] && !isSwap[j]) {
-                isSwap[i] = true;
-                isSwap[j] = true;
-                int tmp = arr[i];
-                arr[i] = arr[j];
-                arr[j] = tmp;
-            }
-        }
-        return arr;
-    }
-
-    // for test
-    public static int[] copyArray(int[] arr) {
-        if (arr == null) {
-            return null;
-        }
-        int[] res = new int[arr.length];
-        for (int i = 0; i < arr.length; i++) {
-            res[i] = arr[i];
-        }
-        return res;
-    }
-
-    // for test
-    public static boolean isEqual(int[] arr1, int[] arr2) {
-        if ((arr1 == null && arr2 != null) || (arr1 != null && arr2 == null)) {
-            return false;
-        }
-        if (arr1 == null) {
-            return true;
-        }
-        if (arr1.length != arr2.length) {
-            return false;
-        }
-        for (int i = 0; i < arr1.length; i++) {
-            if (arr1[i] != arr2[i]) {
-                return false;
-            }
-        }
-        return true;
-    }
-
-    // for test
-    public static void printArray(int[] arr) {
-        if (arr == null) {
-            return;
-        }
-        for (int j : arr) {
-            System.out.print(j + " ");
-        }
-        System.out.println();
-    }
-
-    // for test
-    public static void main(String[] args) {
-        System.out.println("test begin");
-        int testTime = 500000;
-        int maxSize = 100;
-        int maxValue = 100;
-        boolean succeed = true;
-        for (int i = 0; i < testTime; i++) {
-            int k = (int) (Math.random() * maxSize) + 1;
-            int[] arr = randomArrayNoMoveMoreK(maxSize, maxValue, k);
-            int[] arr1 = copyArray(arr);
-            int[] arr2 = copyArray(arr);
-            sortedArrDistanceLessK(arr1, k);
-            comparator(arr2, k);
-            if (!isEqual(arr1, arr2)) {
-                succeed = false;
-                System.out.println("K : " + k);
-                printArray(arr);
-                printArray(arr1);
-                printArray(arr2);
-                break;
-            }
-        }
-        System.out.println(succeed ? "Nice!" : "Fucking fucked!");
-    }
 }
diff --git a/src/test/java/git/snippet/heap/Code_DistanceLessKTest.java b/src/test/java/git/snippet/heap/Code_DistanceLessKTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..a8e91063a5a4a7334a56b4689a90cdb57c3a59fa
--- /dev/null
+++ b/src/test/java/git/snippet/heap/Code_DistanceLessKTest.java
@@ -0,0 +1,58 @@
+package git.snippet.heap;
+
+import git.snippet.common.Generator;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@DisplayName("几乎有序的数组排序测试")
+public class Code_DistanceLessKTest {
+
+    @Test
+    @DisplayName("几乎有序的数组排序测试")
+    public void sortedArrDistanceLessK() {
+        int testTime = 500000;
+        int maxSize = 100;
+        int maxValue = 100;
+        for (int i = 0; i < testTime; i++) {
+            int k = (int) (Math.random() * maxSize) + 1;
+            int[] arr = randomArrayNoMoveMoreK(maxSize, maxValue, k);
+            int[] arr1 = Generator.copyArray(arr);
+            int[] arr2 = Generator.copyArray(arr);
+            Code_DistanceLessK.sortedArrDistanceLessK(arr1, k);
+            Arrays.sort(arr2);
+            Assertions.assertArrayEquals(arr1, arr2);
+        }
+    }
+
+
+    // for test
+    public static int[] randomArrayNoMoveMoreK(int maxSize, int maxValue, int K) {
+        int[] arr = new int[(int) ((maxSize + 1) * Math.random())];
+        for (int i = 0; i < arr.length; i++) {
+            arr[i] = (int) ((maxValue + 1) * Math.random()) - (int) (maxValue * Math.random());
+        }
+        // 先排个序
+        Arrays.sort(arr);
+        // 然后开始随意交换，但是保证每个数距离不超过K
+        // swap[i] == true, 表示i位置已经参与过交换
+        // swap[i] == false, 表示i位置没有参与过交换
+        boolean[] isSwap = new boolean[arr.length];
+        for (int i = 0; i < arr.length; i++) {
+            int j = Math.min(i + (int) (Math.random() * (K + 1)), arr.length - 1);
+            if (!isSwap[i] && !isSwap[j]) {
+                isSwap[i] = true;
+                isSwap[j] = true;
+                int tmp = arr[i];
+                arr[i] = arr[j];
+                arr[j] = tmp;
+            }
+        }
+        return arr;
+    }
+
+}
\ No newline at end of file