Compilare: user.cpp: In function ‘void compute_graph()’: user.cpp:67: warning: comparison between signed and unsigned integer expressions user.cpp:68: warning: comparison between signed and unsigned integer expressions user.cpp:74: warning: comparison between signed and unsigned integer expressions user.cpp:76: warning: comparison between signed and unsigned integer expressions user.cpp:79: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:121: warning: comparison between signed and unsigned integer expressions user.cpp:129: warning: comparison between signed and unsigned integer expressions user.cpp:102: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:103: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:104: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result