From 17a036e65e4184b895250705cb092fb804e90b5d Mon Sep 17 00:00:00 2001
From: ivan <ivan1016017@gmail.com>
Date: Sun, 7 Jun 2026 05:05:28 -0600
Subject: [PATCH] adding updates

---
 .../common_algos/two_sum_round_7.py           |  16 +++
 .../common_algos/valid_palindrome_round_7.py  |  22 ++++
 .../round_6/design_sql.py                     | 102 ++++++++++++++++++
 3 files changed, 140 insertions(+)
 create mode 100644 src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_7.py
 create mode 100644 src/my_project/interviews/amazon_high_frequency_23/common_algos/valid_palindrome_round_7.py
 create mode 100644 src/my_project/interviews/amazon_high_frequency_23/round_6/design_sql.py

diff --git a/src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_7.py b/src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_7.py
new file mode 100644
index 00000000..2d8643f2
--- /dev/null
+++ b/src/my_project/interviews/amazon_high_frequency_23/common_algos/two_sum_round_7.py
@@ -0,0 +1,16 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class Solution:
+    def twoSum(self, nums: List[int], target: int) -> List[int]:
+
+        answer = dict()
+
+        for k, v in enumerate(nums):
+
+            if v in answer:
+                return [answer[v], k]
+            else: 
+                answer[target - v] = k 
+
+        return []
\ No newline at end of file
diff --git a/src/my_project/interviews/amazon_high_frequency_23/common_algos/valid_palindrome_round_7.py b/src/my_project/interviews/amazon_high_frequency_23/common_algos/valid_palindrome_round_7.py
new file mode 100644
index 00000000..b9954582
--- /dev/null
+++ b/src/my_project/interviews/amazon_high_frequency_23/common_algos/valid_palindrome_round_7.py
@@ -0,0 +1,22 @@
+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+import re
+
+class Solution:
+    def isPalindrome(self, s: str) -> bool:
+
+        # To lowercase
+        s = s.lower()
+
+        # Remove non-alphanumeric characters 
+        s = re.sub(pattern=r'[^a-zA-Z0-9]', repl='', string=s)
+
+        # Determine if s is palindrome or not
+        len_s = len(s)
+
+        for i in range(len_s//2):
+
+            if s[i] != s[len_s - 1 - i]:
+                return False
+            
+        return True 
\ No newline at end of file
diff --git a/src/my_project/interviews/amazon_high_frequency_23/round_6/design_sql.py b/src/my_project/interviews/amazon_high_frequency_23/round_6/design_sql.py
new file mode 100644
index 00000000..44d986c9
--- /dev/null
+++ b/src/my_project/interviews/amazon_high_frequency_23/round_6/design_sql.py
@@ -0,0 +1,102 @@
+from typing import List, Union, Collection, Mapping, Optional, Dict
+
+class Table:
+
+    def __init__(self, name:str, columns: int, rows: Dict, row_count: int = 0):
+        self.name = name 
+        self.columns = columns
+        self.rows = rows 
+        self.row_count = row_count
+
+class SQL:
+
+    def __init__(self, names: List[str], columns: List[int]):
+        """
+        two string arrays, names and columns, both of size n.
+
+        The ith table is represented by the name names[i] and contains columns[i] number of columns
+        """
+        self.names = names 
+        self.columns = columns
+        self.data = {}
+
+        for i in range(0, len(self.names)):
+            self.data[self.names[i]] = Table(
+                name = self.names[i],
+                columns=self.columns[i],
+                rows={}
+            )
+
+        return 
+        
+
+    def ins(self, name: str, row: List[str]) -> bool:
+        """
+        Inserts row into the table name and returns true.
+        If row.length does not match the expected number of columns, or name is not a valid table,
+        returns false without any insertion.
+        """        
+        table: Table = self.data.get(name)
+        if table is None:
+            return False 
+        if len(row) != table.columns:
+            return False 
+        table.row_count += 1
+        table.rows[table.row_count] = row
+
+        return True 
+        
+
+    def rmv(self, name: str, rowId: int) -> None:
+        """
+        Removes the row rowId from the table name.
+        If name is not a valid table or there is no row with id rowId, no removal is performed.
+        """        
+        table: Table = self.data.get(name, None)
+        if table is None:
+            return 
+        
+        if rowId in table.rows:
+            del table.rows[rowId]
+
+        return 
+        
+
+    def sel(self, name: str, rowId: int, columnId: int) -> str:
+        """
+        Returns the value of the cell at the specified rowId and columnId in the table name.
+        If name is not a valid table, or the cell (rowId, columnId) is invalid, returns "<null>".
+        """        
+        null = "<null>"
+        table: Table = self.data.get(name, None)
+        if table is None:
+            return null
+        
+        if rowId not in table.rows:
+            return null
+        
+        try:
+            return table.rows[rowId][columnId - 1]
+        except Exception:
+            return null
+        
+
+    def exp(self, name: str) -> List[str]:
+        """
+        Returns the rows present in the table name.
+        If name is not a valid table, returns an empty array.
+        Each row is represented as a string, with each cell value (including the row's id) separated by a ",".
+        """
+        table: Table = self.data.get(name, None)
+        if table is None:
+            return []
+        
+        result = []
+
+        for row_id, row in table.rows.items():
+            row_str = ",".join(row)
+            result.append(f"{row_id},{row_str}")
+        
+        return result
+        
+        
\ No newline at end of file