Compilare: user.cpp: In function ‘int main()’: user.cpp:42: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:44: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘float sum()’: user.cpp:85: warning: comparison between signed and unsigned integer expressions