Compilare: user.cpp: In function ‘int main()’: user.cpp:150:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<strlen(sir);i++) ~^~~~~~~~~~~~ user.cpp:163:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<strlen(sir);i++) ~^~~~~~~~~~~~ user.cpp:174:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<strlen(sir);i++) ~^~~~~~~~~~~~