circular linklist

Author: lyuka

myclinklist.py

@@ -0,0 +1,87 @@
+class CListNode:
+    def __init__( self, data ):
+        self.data = data
+        self.next = None
+
+def traverse( listRef ):
+    curNode = listRef
+    done = listRef is None
+    while not done:
+        curNode = curNode.next
+        print curNode.data,
+        done = curNode is listRef
+    print ''
+
+def searchCircularList( listRef, target ):
+    curNode = listRef
+    done = listRef is None
+    while not done:
+        curNode = curNode.next
+        if curNode.data == target:
+            return True
+        else:
+            done = curNode is listRef or curNode.data > target
+    return False
+
+
+def sortedInsert( listRef, value ):
+    newNode = CListNode( value )
+    if listRef is None:      # empty list
+        listRef = newNode
+        newNode.next = newNode
+    elif value < listRef.next.data:   # insert in front
+        newNode.next = listRef.next
+        listRef.next = newNode
+    elif value > listRef.data:   # insert in back
+        newNode.next = listRef.next
+        listRef.next = newNode
+        listRef = newNode
+    else:
+        preNode = None
+        curNode = listRef
+        done = listRef is None
+        while not done:
+            preNode = curNode
+            curNode = curNode.next
+            done = curNode is listRef or curNode.data > value
+        newNode.next = curNode
+        preNode.next = newNode
+    return listRef
+
+def remove( listRef, target ):
+    assert listRef is not None, "No Node in the link list."
+    preNode = None
+    curNode = listRef
+    done = listRef is None
+    while not done:
+        preNode = curNode
+        curNode = curNode.next
+        if curNode.data == target:
+            if preNode is curNode:
+                listRef = None
+                return listRef
+            preNode.next = curNode.next
+            if curNode is listRef:
+                listRef = preNode
+            return listRef
+        else:
+            done = curNode is listRef or curNode.data > target
+    return listRef
+
+if __name__ == '__main__':
+    #node_a = CListNode(1)
+    listRef = None
+    
+    value = input('insert node( finished with -1): ')
+    while value != -1:
+        listRef = sortedInsert(listRef, value)
+        traverse( listRef )
+        value = input('insert node( finished with -1): ')
+        
+    
+    target = input('remove node( finished with -1): ')
+    while target != -1:
+        listRef = remove( listRef, target )
+        traverse( listRef )
+        target = input('remove node( finished with -1): ')
+