diff --git a/codes/ruby/chapter_array_and_linkedlist/array.rb b/codes/ruby/chapter_array_and_linkedlist/array.rb
index db450eb97..3ad16b1c5 100644
--- a/codes/ruby/chapter_array_and_linkedlist/array.rb
+++ b/codes/ruby/chapter_array_and_linkedlist/array.rb
@@ -45,8 +45,8 @@ end
 ### 删除索引 index 处的元素 ###
 def remove(nums, index)
   # 把索引 index 之后的所有元素向前移动一位
-  for i in index...nums.length
-    nums[i] = nums[i + 1] || 0
+  for i in index...(nums.length - 1)
+    nums[i] = nums[i + 1]
   end
 end
 
diff --git a/docs/chapter_computational_complexity/time_complexity.md b/docs/chapter_computational_complexity/time_complexity.md
index 6241cb483..ee2866b7f 100755
--- a/docs/chapter_computational_complexity/time_complexity.md
+++ b/docs/chapter_computational_complexity/time_complexity.md
@@ -191,11 +191,11 @@
     ```ruby title=""
     # 在某运行平台下
     def algorithm(n)
-        a = 2       # 1 ns 
+        a = 2       # 1 ns
         a = a + 1   # 1 ns
         a = a * 2   # 10 ns
         # 循环 n 次
-        (n...0).each do # 1 ns
+        (0...n).each do # 1 ns
             puts 0      # 5 ns
         end
     end
@@ -516,7 +516,7 @@ $$
     // 算法 C 的时间复杂度：常数阶
     fn algorithm_C(n: i32) void {
         _ = n;
-        for (0..1000000) |_| { 
+        for (0..1000000) |_| {
             std.debug.print("{}\n", .{0});
         }
     }
@@ -690,7 +690,7 @@ $$
         for (int i = 0; i < n; i++) {   // +1（每轮都执行 i ++）
             printf("%d", 0);            // +1
         }
-    }  
+    }
     ```
 
 === "Kotlin"
@@ -1021,13 +1021,13 @@ $T(n)$ 是一次函数，说明其运行时间的增长趋势是线性的，因
 
         // +n（技巧 2）
         for(0..(5 * n + 1)) |_| {
-            std.debug.print("{}\n", .{0}); 
+            std.debug.print("{}\n", .{0});
         }
 
         // +n*n（技巧 3）
         for(0..(2 * n)) |_| {
             for(0..(n + 1)) |_| {
-                std.debug.print("{}\n", .{0}); 
+                std.debug.print("{}\n", .{0});
             }
         }
     }