Compilare: user.cpp: In function ‘bool check(line)’: user.cpp:114: warning: comparison between signed and unsigned integer expressions user.cpp:137: warning: comparison between signed and unsigned integer expressions user.cpp:142: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:181: warning: comparison between signed and unsigned integer expressions user.cpp:183: warning: comparison between signed and unsigned integer expressions user.cpp:233: warning: comparison between signed and unsigned integer expressions user.cpp:250: warning: comparison between signed and unsigned integer expressions user.cpp:257: warning: comparison between signed and unsigned integer expressions user.cpp:175: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:177: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result