Compilare: user.cpp: In function ‘void read()’: user.cpp:13: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void writeandsolve()’: user.cpp:44: warning: comparison between signed and unsigned integer expressions user.cpp:49: warning: comparison between signed and unsigned integer expressions user.cpp:58: warning: comparison between signed and unsigned integer expressions user.cpp:63: warning: comparison between signed and unsigned integer expressions