Compilare: user.cpp: In function ‘int main()’: user.cpp:43:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k = 0; k < G[y].size(); k++) ^ user.cpp:17:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("coach.in", "r", stdin); ^ user.cpp:18:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("coach.out", "w", stdout); ^ user.cpp:21:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &n, &m, &t); ^ user.cpp:23:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^ user.cpp:28:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y, &c); ^