Compilare: user.cpp: In function ‘void citire()’: user.cpp:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void build_graph()’: user.cpp:94: warning: comparison between signed and unsigned integer expressions user.cpp:106: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void solve()’: user.cpp:126: warning: comparison between signed and unsigned integer expressions user.cpp:130: warning: comparison between signed and unsigned integer expressions user.cpp:132: warning: comparison between signed and unsigned integer expressions