Binary Trees

Task1 + task4
                      Mandy
                     /      \
                  Ali       John
                    \       /    \
                   Emma   peter  Susan
                                /    \
                            Robert  Tim
                                      \
                                    William
                                        \
                                       Tom
Task 2
                   50
                  /  \
                25   74
               /  \    \
              17 35    80 
                         \
                         90   
Task 3                             
       If the tree doesn't exist yet, make the DATA ITEM = ROOT NODE and finish.
      Let CURRENT NODE = ROOT NODE.
      Repeat until CURRENT NODE is null.
           If DATA ITEM is less than CURRENT NODE, go to the left.
           Else go to the right.
           CURRENT NODE = value of node reached so far. (Node reached so far = null if there is no node at that position).
      Create new node and add DATA ITEM to that position.