Compilare: user.cpp: In function ‘void prefix()’: user.cpp:20:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<strlen(a);i++){ ^ user.cpp: In function ‘int subsiruri()’: user.cpp:32:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(b);i++){ ^ user.cpp:38:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(q==strlen(a)-1){ ^