Compilare: user.cpp: In function ‘void rec(int, int, int, int)’: user.cpp:24:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i<s.size()&&x1<=x2&&y1<=y2) ^ user.cpp:23:9: warning: variable ‘nr’ set but not used [-Wunused-but-set-variable] int nr,k,q,a,b,c,d,e,f,x,y; ^ user.cpp:23:16: warning: unused variable ‘a’ [-Wunused-variable] int nr,k,q,a,b,c,d,e,f,x,y; ^ user.cpp:23:18: warning: unused variable ‘b’ [-Wunused-variable] int nr,k,q,a,b,c,d,e,f,x,y; ^ user.cpp:23:20: warning: unused variable ‘c’ [-Wunused-variable] int nr,k,q,a,b,c,d,e,f,x,y; ^ user.cpp:23:22: warning: unused variable ‘d’ [-Wunused-variable] int nr,k,q,a,b,c,d,e,f,x,y; ^ user.cpp:23:24: warning: unused variable ‘e’ [-Wunused-variable] int nr,k,q,a,b,c,d,e,f,x,y; ^ user.cpp:23:26: warning: unused variable ‘f’ [-Wunused-variable] int nr,k,q,a,b,c,d,e,f,x,y; ^ user.cpp: In function ‘int main()’: user.cpp:65:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size();i++) ^