Compilare: main.cpp: In function 'void dfs(int, int)': main.cpp:28:26: warning: comparison of constant '2' with boolean expression is always false [-Wbool-compare] if(isAncestor[it]==2) ~~~~~~~~~~~~~~^~~ main.cpp: In function 'int main()': main.cpp:59:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("treespotting.in","r",stdin); ^ main.cpp:60:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("treespotting.out","w",stdout); ^ main.cpp:62:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ main.cpp:69:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^ main.cpp:76:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^