Compilare: user.cpp: In function ‘void kruskal(std::vector<edge, std::allocator<edge> >&, int)’: user.cpp:59: warning: comparison between signed and unsigned integer expressions user.cpp:70: warning: format ‘%lu’ expects type ‘long unsigned int’, but argument 2 has type ‘size_t’ user.cpp: In function ‘int main()’: user.cpp:78: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:79: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:82: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:86: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result