Compilare: user.cpp: In function ‘int par_dreapta(int&)’: user.cpp:20:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=f;i<s.size();++i) ^ user.cpp:30:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(isdigit(s[i]) && i<s.size()){ ^ user.cpp:49:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i>=s.size()) ^ user.cpp: In function ‘int sum(int)’: user.cpp:63:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=f;i<s.size();++i) ^ user.cpp:70:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(isdigit(s[i]) && i<s.size()) ^ user.cpp: In function ‘int par_simplu(int&)’: user.cpp:96:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=f;i<s.size();++i) ^ user.cpp:106:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(isdigit(s[i]) && i<s.size()){ ^ user.cpp: In function ‘int main()’: user.cpp:138:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();++i) ^