matlab : example program to find extreme points of lp problem

format compact;
A=[2 1 1 1 0 0; 1 -2 1  0 1 0; 1 1 0 0 0 1];

b = [ 10; 8; 3];
c= [-1 1 1 0 0 0];

n = 3;
m = 3;

i = 1;
while i <= n+1
        j = i+1;
        while j < n+m
                k=j+1;
                while k <=n+m
                        B=[A(:,[i j k]) b];
                        B=rref(B);
                        temp = [ 0 ; 0 ; 0; 0; 0; 0];
                        x = B(:,[n+1]);
                        fprintf(1,'***Is feasible __ ***');
                        fprintf(1,'i=%d,j=%d,k=%d \n',i,j,k);
                        temp(i) = x(1);
                        temp(j) = x(2);
                        temp(k) = x(3);
                        temp
                        c*temp
                        B=0;
                        x=0;
                        k=k+1;

                end
                j=j+1;
        end
        i=i+1;
end