Merge pull request #73 from csendranshi/master

addition of numbers linkedlist python

GeeksforGeeks/add_numbers_linkedlist.py

@@ -0,0 +1,77 @@
+"""Adding two integers of same length using Linked lists
+
+Example add 321 + 248 = 569
+
+(1)->(2)->(3) + (8)->(4)->(2) = (5)->(6)->(9) """
+
+
+# node definition
+class Node:
+    def __init__(self,data):
+        self.data=data
+        self.next=None
+        # self.head=None
+
+# linkedlist definition
+class LL:
+    def __init__(self):
+        self.head=None
+
+    # method to print the linked list
+    def printLL(self):
+        temp =self.head
+        while(temp):
+            print(temp.data ,end=" ")
+            temp =temp.next
+
+    # method to push a new node onto the linked list
+    def push(self, newdata):
+        newnode = Node(newdata)
+        newnode.next = self.head
+        self.head = newnode
+
+    # method to add the nodes
+    def add(self):
+        carry = []  #to store carry generated if any
+        carry.append(0)
+        temp1 = llist.head
+        temp2 = ll2.head
+        while (temp1 and temp2):
+            sums = temp1.data + temp2.data + carry[-1] #adding the latest element appended to the carry list
+            if (sums >= 0 and sums <= 9):
+                res.push(sums)
+                carry.append(0)
+            else:
+                res.push(sums % 10)
+                carry.append(int(sums / 10))
+
+            temp1 = temp1.next
+            temp2 = temp2.next
+
+        if (carry[-1] != 0):  #if carry is generated : nonzero
+            res.push(carry[-1]) #add it to the res list
+
+llist = LL() #linkedlist 1
+ll2=LL() #linkedlist 2
+res=LL() #linkedlist representing addition of the nodes taken as an integer
+
+
+# adding 321 and 248
+llist.push(3)
+llist.push(2)
+llist.push(1)
+
+ll2.push(2)
+ll2.push(4)
+ll2.push(8)
+
+#Test case for carry generation handling
+# llist.push(9)
+# llist.push(9)
+# llist.push(9)
+# ll2.push(0)
+# ll2.push(0)
+# ll2.push(1)
+
+llist.add()
+res.printLL()