Recently I have been writing a program. It is basically done, but I want to improve its efficiency. I face the following problem. Given an n by 3 real matrix A, I need to find one (but not all) solution x in R^3 of the system of inequalities Ax > 0. (You may assume the system is solvable.) I hope the complexity is at most O(n^2). I tried Fourier-Motzkin method, but then I faced another problem of detecting redundant inequalities; the number of inequalities increases dramatically during the process of Fourier-Motzkin elimination. Any help is appreciated._________________

世上沒有完美的人完美的事，而我們的責任就是要令自己的表演達至最精彩最完美。所以魔術一直都沒有停頓下來，與時代一起進步去追求無止境的完美。