Number of Root to leaf Path

Number of Root to leaf Path

  October 06, 2017    

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Idea is to use tree traversal and whenever a leaf node is detected put length and count into a map

 Map<Integer,Integer> map=new HashMap<Integer,Integer>();
 void path(Node root,int len)
 {
if(root==null)
return;
if(root.left==null && root.right==null)
{
if(map.containsKey(len))
map.put(len,map.get(len)+1);
else
map.put(len,1);
return;
}
// if(root.left!=null)
path(root.left,len+1);
//if(root.right!=null)
path(root.right,len+1);
 }
 void countPaths(Node root)
    {
// map length - no. of path
path(root,1);
for(Map.Entry<Integer,Integer> m:map.entrySet())
{
System.out.print(m.getKey()+" "+m.getValue()+" $");
}
    }