Compilare: user.cpp: In function ‘void citire()’: user.cpp:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:34: 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:103: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void dfs_arbore(int)’: user.cpp:120: warning: comparison between signed and unsigned integer expressions user.cpp:139: warning: comparison between signed and unsigned integer expressions user.cpp:150: warning: comparison between signed and unsigned integer expressions