Compilare: user.cpp: In function ‘int main()’: user.cpp:31: warning: comparison between signed and unsigned integer expressions user.cpp:51: warning: comparison between signed and unsigned integer expressions user.cpp:62: warning: comparison between signed and unsigned integer expressions user.cpp:72: warning: comparison between signed and unsigned integer expressions user.cpp:21: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result