diff --git a/src/main/java/com/cool/ling_cha_mount/sliding_windows/Num1358.java b/src/main/java/com/cool/ling_cha_mount/sliding_windows/Num1358.java
new file mode 100644
index 0000000..ef31a98
--- /dev/null
+++ b/src/main/java/com/cool/ling_cha_mount/sliding_windows/Num1358.java
@@ -0,0 +1,30 @@
+package com.cool.ling_cha_mount.sliding_windows;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/10/30/17:07
+ * @Description:
+ */
+public class Num1358 {
+    public int numberOfSubstrings(String s) {
+        int res = 0;
+        int left = 0;
+        int[] arr = new int[3];
+        for (int i = 0; i < s.length(); i++) {
+            ++arr[s.charAt(i) - 'a'];
+            boolean is = true;
+            for (int a : arr) {
+                is = a != 0;
+                if (!is) break;
+            }
+            if (is) {
+                do {
+                    res += s.length() - i;
+                } while (--arr[s.charAt(left++) - 'a'] != 0);
+            }
+        }
+        return res;
+    }
+}