Khum soln

Q1/solution.py

@@ -1 +1,18 @@
+# Video explaination: https://www.youtube.com/watch?v=2r5YV5h_-1I
 ## Add code below with answer clearly stated
+def fact(n):
+    if n==1:
+        return 1
+    else:
+        return n*fact(n-1)
+def sumDigits(n):
+    if(n==0):
+        return 0
+    mod = n%10
+    return mod + sumDigits((n-mod)/10)
+
+if __name__ == '__main__':
+    i = fact(100)
+    sum = sumDigits(i)
+    print(i) # 93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000
+    print(sum) # 675

Q2/solution.py

@@ -1,8 +1,23 @@
+# Video https://www.youtube.com/watch?v=-HyzeXs3xog
+
+# Executed this solution on leetcode and it worked fine there..
 # Definition for singly-linked list.
 # class ListNode:
 #     def __init__(self, val=0, next=None):
 #         self.val = val
 #         self.next = next
 class Solution:
     def removeNthFromEnd(self, head: Optional[ListNode], n: int) -> Optional[ListNode]:
+        fast = slow = head
+        for _ in range(n):
+            fast = fast.next
+        if not fast:
+            return head.next
+
+        while fast.next:
+            fast = fast.next
+            slow = slow.next
+
+        slow.next = slow.next.next
+        return head
 

Q3/solution.py

@@ -1,3 +1,41 @@
+from typing import List
+
+# code taken from https://github.com/neetcode-gh/leetcode/blob/main/python/4-median-of-two-sorted-arrays.py
+# https://www.youtube.com/watch?v=q6IEA26hvXc video explaination
+# My explaination: https://www.youtube.com/watch?v=yqj1h_kw_KY
+
 class Solution:
     def findMedianSortedArrays(self, nums1: List[int], nums2: List[int]) -> float:
-
+        A, B = nums1, nums2
+        total = len(nums1) + len(nums2)
+        half = total // 2
+
+        if len(B) < len(A):
+            A, B = B, A
+
+        l, r = 0, len(A) - 1
+        while True:
+            i = (l + r) // 2  # A
+            j = half - i - 2  # B
+
+            Aleft = A[i] if i >= 0 else float("-infinity")
+            Aright = A[i + 1] if (i + 1) < len(A) else float("infinity")
+            Bleft = B[j] if j >= 0 else float("-infinity")
+            Bright = B[j + 1] if (j + 1) < len(B) else float("infinity")
+
+            # partition is correct
+            if Aleft <= Bright and Bleft <= Aright:
+                # odd
+                if total % 2:
+                    return min(Aright, Bright)
+                # even
+                return (max(Aleft, Bleft) + min(Aright, Bright)) / 2
+            elif Aleft > Bright:
+                r = i - 1
+            else:
+                l = i + 1
+
+ans = Solution()
+arr1 = [-5, 3, 6, 12, 15]
+arr2 = [-12, -10, -6, -3, 4, 10]
+print("Median of the two arrays is {}".format(ans.findMedianSortedArrays(arr1, arr2)))