float Cj[N],Ci[N];
float C[N][N];
a = (float**) malloc(N*sizeof(float));
a = (float**) malloc(N*sizeof(float *));
20*cos(8*Ci+3)+10*cos(5*Cj+7);
20*cos(8*C[i]+3)+10*cos(5*C[j]+7);
float ci, cj;