Compilare: user.cpp: In function ‘int main()’: user.cpp:22:9: warning: unused variable ‘L’ [-Wunused-variable] int L,l; ^ user.cpp:24:9: warning: unused variable ‘a’ [-Wunused-variable] int a=1; ^ user.cpp:23:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &t); ^ user.cpp:34:28: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%c", &c); ^