Compilare: user.cpp: In member function ‘void DominatorTree::step1(const std::vector<std::vector<int> >&, int)’: user.cpp:103:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (ei != graph[v].size()) { ^ user.cpp: In function ‘int main()’: user.cpp:182:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colonii.in", "r", stdin); ^ user.cpp:183:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colonii.out", "w", stdout); ^ user.cpp:186:45: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int n, m, c; scanf("%d%d%d", &n, &m, &c); c--; ^ user.cpp:189:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int x, y; scanf("%d%d", &x, &y); x--; y--; ^