Compilare: user.cpp: In function ‘int main()’: user.cpp:28:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1; i<=strlen(lu+1); i++) ^ user.cpp:34:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=i+1; j<=strlen(lu+1); j++) ^ user.cpp:41:55: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( k=j+1; k<=strlen(lu+1); k++) ^ user.cpp:139:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] fo(strlen(lu+1)) ^ user.cpp:9:30: note: in definition of macro ‘fo’ #define fo(a) for(int i=1;i<=a;i++) ^ user.cpp:147:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i==strlen(lu+1))out<<'\n'; ^ user.cpp:155:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1; i<=strlen(lu+1); i++) ^ user.cpp:159:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=i+1; j<=strlen(lu+1); j++) ^ user.cpp:167:61: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( k=j; k<=strlen(lu+1); k++) ^ user.cpp:174:54: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(k==strlen(lu+1))out<<'\n';} ^ user.cpp:177:59: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for( k=j+1; k<=strlen(lu+1); k++) ^ user.cpp:16:9: warning: unused variable ‘n’ [-Wunused-variable] int n,i,j,k,d=1,nr=0,t,luv; ^ user.cpp:16:17: warning: unused variable ‘d’ [-Wunused-variable] int n,i,j,k,d=1,nr=0,t,luv; ^