Compilare: user.cpp: In function ‘int eval()’: user.cpp:35:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(c<=s.size()) ^ user.cpp:37:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(c==s.size()||s[c]==')') {c++;return curr;} ^ user.cpp: In function ‘int termen()’: user.cpp:31:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int eval()’: user.cpp:46:1: warning: control reaches end of non-void function [-Wreturn-type] } ^