Driver method
let arr = new Array ( 5 ) ; for ( let i = 0 ; i < arr . length ; i ++ ) { arr [ i ] = new Array ( 2 ) ; for ( let j = 0 ; j < 2 ; j ++ ) { arr [ i ] [ j ] = 0 ; } } arr [ 0 ] [ 0 ] = 11 ; arr [ 0 ] [ 1 ] = 20 ; arr [ 1 ] [ 0 ] = 30 ; arr [ 1 ] [ 1 ] = 40 ; arr [ 2 ] [ 0 ] = 5 ; arr [ 2 ] [ 1 ] = 10 ; arr [ 3 ] [ 0 ] = 40 ; arr [ 3 ] [ 1 ] = 30 ; arr [ 4 ] [ 0 ] = 10 ; arr [ 4 ] [ 1 ] = 5 ; findSymPairs ( arr ) ;