diff --git a/util/index.mjs b/util/index.mjs
index 861ae76..3868ef2 100644
--- a/util/index.mjs
+++ b/util/index.mjs
@@ -70,5 +70,28 @@ export function swap(array, a, b) {
   }
   
 
-
-
+  export function isSort(arr) {
+    const len = arr.length
+    let isInverted = false
+    if(len <2) {
+      return true
+    }
+    // 判断数组是否倒序
+    if(arr[0] > arr[1]) {
+      isInverted = true
+    }
+    if(isInverted) {
+      for(let i=0;i<len-1;i++){
+        if(arr[i]<arr[i+1]){
+          return false
+        }
+      }
+    }else{
+      for(let i=0;i<len-1;i++){
+        if(arr[i]>arr[i+1]){
+          return false
+        }
+      }
+    }
+    return true
+  }