Compilare: main.cpp: In function 'int main()': main.cpp:67:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G[1].size(); ++i) { ~~^~~~~~~~~~~~~ main.cpp:75:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G[1].size(); ++i) { ~~^~~~~~~~~~~~~ main.cpp:79:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (ind == -1 && i < G[1].size() - 1) ~~^~~~~~~~~~~~~~~~~ main.cpp:53:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("invtree.in", "r", stdin); ^ main.cpp:54:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("invtree.out", "w", stdout); ^ main.cpp:57:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &h); ^ main.cpp:60:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &u, &v, &c); ^