fix: solved potential bugs

03. Arrays/3.2. Medium/1. TwoSum.py

@@ -1,12 +1,12 @@
-def read(n: int, book: [int], target: int) -> str:
+def read(n: int, book: list[int], target: int) -> str:
     # Write your code here.
     d = {}
-    for i, n in enumerate(book):
-        rem = target - n
+    for i, num in enumerate(book):
+        rem = target - num
         if rem in d.keys():
             return "YES"
         else:
-            d[n] = i
+            d[num] = i
     return "NO"
 
 # Link: https://www.codingninjas.com/studio/problems/reading_6845742

03. Arrays/3.3. Hard/11. CountInversions.py

@@ -46,9 +46,6 @@ def mergeSort(arr : List[int], low : int, high : int) -> int:
     return cnt
 
 def numberOfInversions(a : List[int], n : int) -> int:
-    # Count the number of pairs:
-    n = len(a)
-    # Count the number of pairs:
     return mergeSort(a, 0, n - 1)
 
 if __name__ == "__main__":

03. Arrays/3.3. Hard/3. 3Sum.py

@@ -1,86 +1,46 @@
-def triplet(n: int, nums: [int]) -> [[int]]:
+from typing import List
+
+def triplet(n: int, nums: List[int]) -> List[List[int]]:
     # Write your code here.
     res = set()
 
-    # Spliting
-    n, p, z = [], [], []
+    # Splitting the input list into negative, positive, and zero lists
+    neg, pos, zero = [], [], []
     for i in nums:
-        if i>0:
-            p.append(i)
-        elif i<0:
-            n.append(i)
+        if i > 0:
+            pos.append(i)
+        elif i < 0:
+            neg.append(i)
         else:
-            z.append(i)
+            zero.append(i)
 
-    N, P = set(n), set(p)
+    # Converting lists to sets for faster lookups
+    N, P = set(neg), set(pos)
 
-    # Case1: p, 1z, n
-    if z:
+    # Case 1: One positive, one negative, and one zero
+    if zero:
         for num in P:
-            if -1*num in N:
-                res.add((-1*num, 0, num))
+            if -num in N:
+                res.add((-num, 0, num))
 
-
-    # Case2: 0, 0, 0
-    if len(z)>=3:
-        res.add((0,0,0))
+    # Case 2: Three zeros
+    if len(zero) >= 3:
+        res.add((0, 0, 0))
 
-    # Case 3: 2 negatives == 1 positive
-    for i in range(len(n)):
-        for j in range(i+1, len(n)):
-            t = -1*(n[i] + n[j])
+    # Case 3: Two negatives sum to a positive
+    for i in range(len(neg)):
+        for j in range(i + 1, len(neg)):
+            t = -1 * (neg[i] + neg[j])
             if t in P:
-                res.add(tuple(sorted([n[i], n[j], t])))
+                res.add(tuple(sorted([neg[i], neg[j], t])))
 
-    # Case 4: 2 positive == 1 negative
-    for i in range(len(p)):
-        for j in range(i+1, len(p)):
-            t = -1*(p[i] + p[j])
+    # Case 4: Two positives sum to a negative
+    for i in range(len(pos)):
+        for j in range(i + 1, len(pos)):
+            t = -1 * (pos[i] + pos[j])
             if t in N:
-                res.add(tuple(sorted([p[i], p[j], t])))
-
-    return list(map(list, res))
-
-# Link: https://www.codingninjas.com/studio/problems/three-sum_6922132
-
-# Optimal Approach
-# def triplet(n, arr):
-#     ans = []
-#     arr.sort()
-#     for i in range(n):
-#         # remove duplicates:
-#         if i != 0 and arr[i] == arr[i - 1]:
-#             continue
-
-#         # moving 2 pointers:
-#         j = i + 1
-#         k = n - 1
-#         while j < k:
-#             total_sum = arr[i] + arr[j] + arr[k]
-#             if total_sum < 0:
-#                 j += 1
-#             elif total_sum > 0:
-#                 k -= 1
-#             else:
-#                 temp = [arr[i], arr[j], arr[k]]
-#                 ans.append(temp)
-#                 j += 1
-#                 k -= 1
-#                 # skip the duplicates:
-#                 while j < k and arr[j] == arr[j - 1]:
-#                     j += 1
-#                 while j < k and arr[k] == arr[k + 1]:
-#                     k -= 1
-
-#     return ans
+                res.add(tuple(sorted([pos[i], pos[j], t])))
 
+    # Convert set of tuples to list of lists
+    return [list(triplet) for triplet in res]
 
-# arr = [-1, 0, 1, 2, -1, -4]
-# n = len(arr)
-# ans = triplet(n, arr)
-# for it in ans:
-#     print("[", end="")
-#     for i in it:
-#         print(i, end=" ")
-#     print("]", end=" ")
-# print()

04. BinarySearch/4.2. BinarySearchAns/7. KthMissing.py

@@ -1,8 +1,7 @@
-from typing import *
+from typing import List
 
 def missingK(vec: List[int], n: int, k: int) -> int:
     # Write your code here.
-    n = len(vec)
     low = 0
     high = n-1        
     missing = 0

05. Strings/5.1. BasicProblems/4. LargestPrefix.py

@@ -1,9 +1,8 @@
 from typing import List
 
-def commonPrefix(inp: List[str], n: int) -> str:
+def commonPrefix(inp: List[str], n: int) -> str | int:
     # Write your code here
     ans = ""
-    n = len(inp)
     mini = len(min(inp, key=len))
     for i in range(mini):
         mainchar = inp[0][i]