Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:45:50: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < query[node].size(); i++) ^ user.cpp: In function ‘void readInput(int, int)’: user.cpp:63:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(input); ^ user.cpp:64:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(input); ^ user.cpp:82:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(input); ^ user.cpp:103:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp: In function ‘int main()’: user.cpp:110:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbvalmax.in", "r", stdin); ^ user.cpp:111:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbvalmax.out", "w", stdout); ^ user.cpp:114:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ /tmp/ccEXLzpg.o: In function `readInput(int, int)': user.cpp:(.text+0x9c): warning: the `gets' function is dangerous and should not be used.