24-01-2012, 12:45 PM
DISCRETE STRUCTURE
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Its properties
-Its edge are called BRANCHES.
-A tree with only one vertex is called
a TRIVIAL TREE otherwise T is a NONTRIVIAL TREE.
-There is only one path between every pair of vertices in a TREE.
-A TREE T with n vertices has n-1 edgs.
ROOTED TREES
A rooted tree is a tree in which a particular vertex is distinguished from the others and is called the root.
Natural tree grow upwards from the ground into the air .
But tree data structure downwards from top to bottom.
Fundamental principles
SUM RULE
If an event can occur in m ways and another event can occur in n ways , if two of the event can not occur simultaneously ,than one of the two event can occur in (m+n) ways .
Example::If there are 14 boys and 12 girls in a class , find the number of ways of selecting one student as class representative.?
Solution::Using sum rule there are 4+5=9 ways of choosing one of the college.