Compilare: user.cpp: In function ‘int main()’: user.cpp:77:10: warning: variable ‘c’ set but not used [-Wunused-but-set-variable] char c; ^ user.cpp: In function ‘int exp()’: user.cpp:34:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int termen()’: user.cpp:70:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:78:22: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s1,1000,in); ^ user.cpp:79:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d",&n); ^ user.cpp:81:20: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(v,100,in); ^