Compilare: main.cpp: In function 'void solve()': main.cpp:75:9: warning: unused variable 'sons' [-Wunused-variable] int sons=0; ^~~~ main.cpp: In function 'int main()': main.cpp:138:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("treegcd.in","r",stdin); ^ main.cpp:139:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("treegcd.out","w",stdout); ^ main.cpp:141:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ main.cpp:147:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^