Compilare: main.cpp: In function 'void getCentroid(int, int, int)': main.cpp:108:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < L[node].size(); ++i) ~~^~~~~~~~~~~~~~~~ main.cpp:117:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < L[node].size(); ++i) ~~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:132:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("flareon.in", "r", stdin); ^ main.cpp:133:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("flareon.out", "w", stdout); ^ main.cpp:138:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &M); ^ main.cpp:141:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ main.cpp:148:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^