Compilare: user.cpp: In function ‘void combine(std::vector<int>&, std::vector<int>&)’: user.cpp:41:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < source.size(); i++) ^ user.cpp: In function ‘void dfs(int)’: user.cpp:68:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < list[node].size(); i++) { ^ user.cpp:114:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 1; i < list[node].size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:128:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("treemis.in","r",stdin); ^ user.cpp:129:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("treemis.out","w",stdout); ^ user.cpp:131:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:132:48: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (i = 1; i <= n; i++) scanf("%d", &v[i]); ^ user.cpp:134:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); x++; y++; ^