Create dsa.py

made a change in idea

algorithms/Python/dictionaries/dsa.py

@@ -0,0 +1,25 @@
+def two_sum(nums, target):
+    # Create a dictionary to store the elements and their indices
+    num_dict = {}
+
+    # Traverse the array
+    for i, num in enumerate(nums):
+        # Calculate the complement required to reach the target
+        complement = target - num
+
+        # Check if the complement exists in the dictionary
+        if complement in num_dict:
+            # Return the indices of the two numbers that add up to the target
+            return [num_dict[complement], i]
+        
+        # Store the current element and its index in the dictionary
+        num_dict[num] = i
+
+    # If no pair is found, return [-1, -1]
+    return [-1, -1]
+
+# Test example
+nums = [2, 7, 11, 15]
+target = 9
+result = two_sum(nums, target)
+print(result)  # Output: [0, 1] (Because nums[0] + nums[1] = 2 + 7 = 9)