Compilare: main.cpp: In function 'int main()': main.cpp:69:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<v.size()) ~^~~~~~~~~ main.cpp:47:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("rubarba.in","r",stdin); ^ main.cpp:48:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("rubarba.out","w",stdout); ^ main.cpp:50:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ main.cpp:53:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^