[R] Simulation study in R

[Arun Kumar Saha]

Here I am in a simulation study where I want to find different values
of x and y such that f(x,y)=c (some known constant) w.r.t. x, y >0,
y<=x and x<=c1 (another known constant). Can anyone please tell me how
to do it efficiently in R. One way I thought that I will draw
different random numbers from uniform dist according to that
constraints and pick those which satisfy f(x,y)=c. However it is not I
think computationally efficient. Can anyone here suggest me any other
efficient approach?

Regards,