Compilare: user.cpp: In function ‘void bell()’: user.cpp:32: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void dfs2(int, int)’: user.cpp:52: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void dfs1(int)’: user.cpp:62: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:90: warning: comparison between signed and unsigned integer expressions user.cpp:110: warning: comparison between signed and unsigned integer expressions user.cpp:76: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:79: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result