Compilare: user.cpp: In function ‘int main()’: user.cpp:44:6: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] s2[k]=NULL; ^ user.cpp:50:14: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] s2[k]=NULL;}} ^ user.cpp:51:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<strlen(s2)-1; i++) ^ user.cpp:52:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=i+1; j<strlen(s2); j++) ^ user.cpp:64:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<strlen(s); j++) ^ user.cpp:68:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<strlen(s); i++) ^ user.cpp:75:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(x[i].b>=strlen(s)) ^ user.cpp: In function ‘void ordonareb(int, interval*)’: user.cpp:31:2: warning: ‘gata’ is used uninitialized in this function [-Wuninitialized] while(!gata); ^