---

Author: Sagar Paul

DSA-problems/01.py

@@ -0,0 +1,55 @@
+# Find nth last Node from the end of the Linkedlist
+
+class Node:
+    def __init__(self,data):
+        self.data = data
+        self.next = None
+
+class Linkedlist:
+
+    def __init__(self):
+        self.head = None
+
+    def node_from_end(self):
+        if self.head is None:
+            print("The Linkedlist is Empty!")
+        else:
+            temp = self.head
+            samir = self.head
+            for i in range(n-1):
+                temp = temp.next
+            while temp.next is not None:
+                temp = temp.next
+                samir = samir.next
+            print(f"The {n}th node from the end of the linkedlist is {samir.data}")
+
+    def add_begine(self,data):
+        if self.head is None:
+            self.head = Node(data)
+        else:
+            new_node = Node(data)
+            new_node.next = self.head
+            self.head = new_node
+
+n = int(input("Type the value of n to find  nth last element of this Linkedlist:  "))
+
+LL1 = Linkedlist()
+LL1.add_begine(15)
+LL1.add_begine(14)
+LL1.add_begine(13)
+LL1.add_begine(12)
+LL1.add_begine(11)
+LL1.add_begine(10)
+LL1.add_begine(9)
+LL1.add_begine(8)
+LL1.add_begine(7)
+LL1.add_begine(6)
+LL1.add_begine(5)
+LL1.add_begine(4)
+LL1.add_begine(3)
+LL1.add_begine(2)
+LL1.add_begine(1)
+
+print(LL1.node_from_end())
+
+

DSA-problems/23_Printing Stars in Right Triangle Shape Using while loop.py

@@ -0,0 +1,13 @@
+sentence = input("Type a sentence here:     ")
+s = sentence.lower()
+list1 = ["a", "e", "i", "o", "u"]
+
+count = 0
+for char in s:
+    if char in list1:
+        count = count +1
+
+print(count)
+
+
+

LinkedList/Find nth last Node from the end of a Singly Linkedlist.py

@@ -0,0 +1,4 @@
+a = ["Samir", 1,3,4,3,4,2,4,2,42,11,1,442,1,3844444]
+
+s = [i for i in range(len(a)) if a[i] ==4]
+print(s)

Python Problem Solving/46_To Count The Vowels in Given Sentence .py

@@ -0,0 +1,22 @@
+def BinerySearch(l,key):
+    low = 0
+    high = len(l) - 1
+    found = False
+    while low<=high and not found:
+        mid = (low + high)//2
+        if key == l[mid]:
+            found = True
+        elif key < l[mid]:
+            high = mid -1
+        else:
+            low = mid + 1
+    if found == True:
+        print("The value is found.")
+    else:
+        print("Value is not found!")
+    
+l = [2,3,4,6,64,24,453,33,4242,21]
+l.sort()
+print(l)
+key = int(input("Enter the value of key:  ")) 
+BinerySearch(l,key)

Python Problem Solving/47_To Print Every Index of Duplicate Elements in List.py

@@ -0,0 +1,20 @@
+def BinarySearch(l,key):
+    low = 0
+    high = len(l)-1
+    found = False
+    while low<=high and not found:
+        mid = (low+high)//2
+        if key == l[mid] :
+            found = True
+        elif key < l[mid]:
+            high = mid -1
+        elif key > l[mid]:
+            low = mid +1
+    if found ==True:
+        print(f"The key {key} is found!")
+    else:
+        print(f"The key {key} is NOT found.")
+
+l = [1,2,4,5,97,324,5464,5555555]
+#key = int(input("enter a value within the list:  "))
+BinarySearch(l,5)

Python Problem Solving/48_Binary Search in Python.py

@@ -0,0 +1,23 @@
+def BinarySearch(l,key):
+    low = 0
+    high = len(l)-1
+    mid = (low+high)//2
+    found = False
+    while low<=high and not found:
+        mid = (low+high)//2
+        if key == l[mid] :
+            mid = mid -1
+            found = True
+        elif key < l[mid]:
+            high = mid -1
+        elif key > l[mid]:
+            low = mid +1
+    if found ==True:
+        print("The key is found!")
+        print(mid)
+    else:
+        print("The key is not found.")
+
+l = [1,2,4,5,97,97,97,97,97,324,5464,5555555]
+#key = int(input("enter a value within the list:  "))
+BinarySearch(l,97)

Python Problem Solving/49_Binary_Search.py

@@ -0,0 +1,21 @@
+def roman_number(num):
+    if num > 3999:
+        print("Enter a number below 3999")
+    else:
+        value = [1000,900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1]
+        symbol = ["M","CM","D","CD","C","XC","L","XL","X","IX","V","IV","I"]
+        roman = ""
+        i = 0
+        while num >0:
+            div = num//value[i]
+            num = num% value[i]
+            while div:
+                roman  = roman +symbol[i]
+                div = div - 1
+            i = i+1
+        return roman
+
+num = int(input("Write a number here: \n"))
+print(roman_number(num))
+
+