diff --git a/leetcode/3347/solution.hpp b/leetcode/3347/solution.hpp
index 97fc5f3..5690cfc 100644
--- a/leetcode/3347/solution.hpp
+++ b/leetcode/3347/solution.hpp
@@ -12,7 +12,7 @@ struct Solution {
             if (i > 0 && nums[i - 1] == nums[i]) {
                 continue;
             }
-            // 只有nums中每个数n及n±k，可能达到最大频率
+            // 只有nums中的数n及n±k，可能达到最大频率
             for (int cn : {nums[i] - k, nums[i], nums[i] + k}) {
                 if (cn < nums.front() || cn > nums.back()) {
                     continue;
diff --git a/leetcode/3461/case.yaml b/leetcode/3461/case.yaml
new file mode 100644
index 0000000..1ca8b90
--- /dev/null
+++ b/leetcode/3461/case.yaml
@@ -0,0 +1,24 @@
+example1:
+  input:
+    s: "3902"
+  expected: true
+
+example2:
+  input:
+    s: "34789"
+  expected: false
+
+regression1:
+  input:
+    s: "4867716181911413979960155821878"
+  expected: true
+
+regression2:
+  input:
+    s: "472371665226339635424494604455723348326857778972516313101962164"
+  expected: true
+
+regression3:
+  input:
+    s: "4802870269162891409411160836125514611"
+  expected: true
diff --git a/leetcode/3461/solution.hpp b/leetcode/3461/solution.hpp
new file mode 100644
index 0000000..d53be6f
--- /dev/null
+++ b/leetcode/3461/solution.hpp
@@ -0,0 +1,13 @@
+#include <string>
+
+struct Solution {
+    bool hasSameDigits(std::string s) {
+        while (s.size() > 2) {
+            for (std::size_t i{0}; i < s.size() - 1; ++i) {
+                s[i] = ((s[i] - '0') + (s[i + 1] - '0')) % 10 + '0';
+            }
+            s.pop_back();
+        }
+        return s[0] == s[1];
+    }
+};