Compilare: main.cpp: In function 'int main()': main.cpp:75:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < lev[l].size(); ++i) { ~~^~~~~~~~~~~~~~~ main.cpp:15:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("bazar.in", "r", stdin); ^ main.cpp:16:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("bazar.out", "w", stdout); ^ main.cpp:17:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] int n, k = 0; scanf("%d", &n); ^ main.cpp:19:48: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &pts[i].first, &pts[i].second); ^