Compilare: user.cpp: In function ‘void read()’: user.cpp:36: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:41: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp: In function ‘void solve()’: user.cpp:57: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void up(int)’: user.cpp:70: warning: unused variable ‘ax’ user.cpp: In function ‘void dijkstra()’: user.cpp:124: warning: comparison between signed and unsigned integer expressions