Create Root the Tree.java

Author: Sushank34

Codechef/LTIME88B/Root the Tree.java

@@ -0,0 +1,98 @@
+import java.util.*;
+import java.lang.*;
+import java.io.*;
+
+class Codechef
+{
+    static class FastReader 
+    { 
+        BufferedReader br; 
+        StringTokenizer st; 
+  
+        public FastReader() 
+        { 
+            br = new BufferedReader(new
+                     InputStreamReader(System.in)); 
+        } 
+  
+        String next() 
+        { 
+            while (st == null || !st.hasMoreElements()) 
+            { 
+                try
+                { 
+                    st = new StringTokenizer(br.readLine()); 
+                } 
+                catch (IOException  e) 
+                { 
+                    e.printStackTrace(); 
+                } 
+            } 
+            return st.nextToken(); 
+        } 
+  
+        int nextInt() 
+        { 
+            return Integer.parseInt(next()); 
+        } 
+  
+        long nextLong() 
+        { 
+            return Long.parseLong(next()); 
+        } 
+  
+        double nextDouble() 
+        { 
+            return Double.parseDouble(next()); 
+        } 
+  
+        String nextLine() 
+        { 
+            String str = ""; 
+            try
+            { 
+                str = br.readLine(); 
+            } 
+            catch (IOException e) 
+            { 
+                e.printStackTrace(); 
+            } 
+            return str; 
+        } 
+    } 
+	public static void main (String[] args) throws java.lang.Exception
+	{
+		// your code goes here
+		FastReader sc=new FastReader();
+		int t=sc.nextInt();
+		while(t-->0) {
+			int n=sc.nextInt();
+			int[] fr=new int[n-1];
+			int[] to=new int[n-1];
+			for(int i=0;i<n-1;i++) {
+				fr[i]=sc.nextInt();
+				to[i]=sc.nextInt();
+			}
+			Dictionary d= new Hashtable();
+			int temp;
+			for(int i=0;i<n-1;i++) {
+				if(d.get(to[i])==null) {
+					d.put(to[i],1);
+				}
+				else {
+					temp=(int) d.get(to[i]);
+					d.put(to[i],temp+1);
+				}
+			}
+			int s=0;
+			for (Enumeration i = d.elements(); i.hasMoreElements();) 
+	        { 
+	            temp=(int) i.nextElement();
+	            if(temp>1) {
+	            	s=s+temp-1;
+	            }
+	        }
+			System.out.println(s);
+		}
+	}
+}