Consider an array composed of unique numbers. The objective is to identify

all ordered pairs $($x$,$ y$)$ within this array where the remainder of the division of the

first number $($x$)$ by the second number $($y$)$ equals a specified integer, r$.$

Example $1$:$-$ arr$[]=\{4,5,2,1,3\}$ and r $=2,$ the output should be $(2,3),(2,5),(5,3),(2,4).$

Example $2$:$-$ arr$[]=\{6,1,4,10,9\}$ and r $=2.$ The output is the set of pairs

$(6,4),(10,4)$

The length of the array n is such that $1<=$ n $<=10^6$

and range of r $1<=$ k $<=10^6$