**1.Convex hull->O(nlog n):Graham Scan.**

2.Point inside a polygon->O(n):Crossing number method.

3.Center of Gravity(UVa 10002)->O(nlog n).

4.Finding closest pair of points->O(nlog n).

5.From a large number of points,what is the number of maximum points on a line->O(n^2*log (n^2)).

6.Minimum circle enclosing n points->O(nlog n)+O(h^3),where h is the number of points on convex-hull.

7.Line segment intersection.

2.Point inside a polygon->O(n):Crossing number method.

3.Center of Gravity(UVa 10002)->O(nlog n).

4.Finding closest pair of points->O(nlog n).

5.From a large number of points,what is the number of maximum points on a line->O(n^2*log (n^2)).

6.Minimum circle enclosing n points->O(nlog n)+O(h^3),where h is the number of points on convex-hull.

7.Line segment intersection.

I want to know what should i learn more,because i am going to participate in the Dhaka regional-07.Should i learn line clipping(Cohen-Sutherland),common area of two polygon,trelayny triangulation,voronoi diagram etc.?Please mention any useful links,books etc.I wiil be very glad if u also mention the best run time of the algo's.Thanks in advance.