diff --git a/week4/how-many-numbers-are-smaller-than-the-current-number.py b/week4/how-many-numbers-are-smaller-than-the-current-number.py
new file mode 100644
index 0000000..e2ed6b0
--- /dev/null
+++ b/week4/how-many-numbers-are-smaller-than-the-current-number.py
@@ -0,0 +1,12 @@
+class Solution:
+    def smallerNumbersThanCurrent(self, nums: List[int]) -> List[int]:
+        sorted_nums=sorted(nums)
+        dic={}
+        for i,num in enumerate(sorted_nums):
+            if not num in dic:
+                dic[num]=i
+        ans=[]
+        for num in nums:
+            ans.append(dic[num])
+        return ans
+        
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