I want to make the program about Physics:

initial value: x(0),y(0),vx(0),vy(0)

I can find r(0)=x(0)+y(0),ax(0)=x(0)/r(0),ay(0)=y(0)/r(0)

Then,I find vx(t/2)=vx(0)+ax(0)*t,vy(t/2)=vy(0)+ay(0)*t

Therefore,I can calculate x(t)=x(0)+vx(t/2)*t,y(t)=y(0)+vy(t/2)*t

then, r(t)=x(t)+y(t),ax(t)=x(t)/r(t),ay(t)=y(t)/r(t)

vx(t/2+t)=vx(t/2)+ax(t)*t,vy(t/2+t)=vy(t/2)+ay(t)*t

again,x(2t)=x(t)+vx(3t/2)*t,y(2t)=y(t)+vy(3t/2)*t

r(2t)=x(2t)+y(2t),ax(2t)=x(2t)/r(2t),ay(2t)=y(2t)/r(2t)

vx(3t/2+t)=vx(3t/2)+ax(2t)*t,vy(3t/2+t)=vy(3t/2)+ay(2t)*t...

It's only vx(t/2),vy(t/2) have different calculation methods,

but other's will cycle like this:0→t,t→2t,2t→3t;

vx(3t/2),vy(3t/2) will cycle: 3t/2→5t/2,5t/2→7t/2,7t/2→9t/2.

I want Dev C++ print all x(t),y(t) until t<T.

However,the relation between x,y,r,vx,vy,ax,ay makes me crazy.

I have tried many many hours, and I hope someone can help me.

I will very grateful to you!