diff --git a/src/main/java/com/cool/ling_cha_mount/binary_search/Num1170.java b/src/main/java/com/cool/ling_cha_mount/binary_search/Num1170.java
new file mode 100644
index 0000000..c8499ee
--- /dev/null
+++ b/src/main/java/com/cool/ling_cha_mount/binary_search/Num1170.java
@@ -0,0 +1,34 @@
+package com.cool.ling_cha_mount.binary_search;
+
+public class Num1170 {
+    public int[] numSmallerByFrequency(String[] queries, String[] words) {
+        int[] count = new int[12];
+        for (String str : words) {
+            count[f(str)]++;
+        }
+        for (int i = 9; i > 0; i--) {
+            count[i] += count[i + 1];
+        }
+        int[] res = new int[queries.length];
+        for (int i = 0; i < queries.length; i++) {
+            int c = f(queries[i]);
+            res[i] = count[c + 1];
+        }
+        return res;
+    }
+
+    private int f(String s) {
+        char current = 'z';
+        int count = 0;
+        for (int i = 0; i < s.length(); i++) {
+            char cur = s.charAt(i);
+            if (cur < current) {
+                current = cur;
+                count = 1;
+            } else if (cur == current) {
+                count++;
+            }
+        }
+        return count;
+    }
+}