Driver Code
public static void Main ( String [ ] args ) { int [ , ] edges = { { 1 , 2 } , { 1 , 3 } , { 2 , 4 } } ; for ( int i = 0 ; i < adj . GetLength ( 0 ) ; i ++ ) adj [ i ] = new List < int > ( ) ; countPairs ( edges ) ; } }