Compilare: user.cpp: In function ‘bool is_ok(int, int)’: user.cpp:20:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i<0 || j<0 || i >= poz_y.size() - 1 || j >= poz_x.size() - 1) ^ user.cpp:20:68: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i<0 || j<0 || i >= poz_y.size() - 1 || j >= poz_x.size() - 1) ^ user.cpp: In function ‘int solve()’: user.cpp:42:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < poz_y.size() - 1; ++i) ^ user.cpp:43:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j< poz_x.size() - 1; ++j){ ^ user.cpp: In function ‘void fa_ma_matrice()’: user.cpp:72:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int k=0; k<drept.size(); k++) ^ user.cpp:71:13: warning: unused variable ‘k’ [-Wunused-variable] int i,j,k; ^