diff --git a/docs/chapter_computational_complexity/time_complexity.md b/docs/chapter_computational_complexity/time_complexity.md
index db2c5614d..fa07bd542 100644
--- a/docs/chapter_computational_complexity/time_complexity.md
+++ b/docs/chapter_computational_complexity/time_complexity.md
@@ -2337,7 +2337,7 @@ $$
         }
         // 随机打乱数组元素
         for (let i = 0; i < n; i++) {
-            let r = Math.floor(Math.random() * n);
+            let r = Math.floor(Math.random() * (i + 1));
             let temp = nums[i];
             nums[i] = nums[r];
             nums[r] = temp;
@@ -2381,7 +2381,7 @@ $$
         }
         // 随机打乱数组元素
         for (let i = 0; i < n; i++) {
-            let r = Math.floor(Math.random() * n);
+            let r = Math.floor(Math.random() * (i + 1));
             let temp = nums[i];
             nums[i] = nums[r];
             nums[r] = temp;