Voronoi, Delaunuy Triangulation in 2D and 3D

We need to give one point at each time, then ask for another one and connect the first one with the closest point and then ask for another one and connect it to the closest one. Afterwards, when points are connected we have the triangle and we will ask for another one point and to calculate which of the other points are the closest one and connect them together. (So we have another one triangle attached to the first triangle) For each side of the triangle we have to find the perpedicular line and draw it(vertical right angle of the sideline of each triangle). We need to find the middle point of all the perpedicular lines and then we need to draw a line from the middle of the first perpedicular to the second one. Then, we have to draw circles over and attached of the points of each triangles. The points will be given by the user, the amount is not specified. The user can give as much points as he wants in a loop. All these are according to the Voronoi and Delaunuy Theories. We need to use the graphics.h library and C/C++