Compilare: main.cpp:46:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type] main() ^ main.cpp: In function 'int main()': main.cpp:61:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; sol.size() < (n-1); ++i) ~~~~~~~~~~~^~~~~~~ main.cpp:48:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("apm.in", "rt", stdin); ^ main.cpp:49:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("apm.out", "wt", stdout); ^ main.cpp:51:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:54:51: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &v[i].a, &v[i].b, &v[i].d); ^