Compilare: main.cpp: In function 'std::vector<int> mult(std::vector<int>, std::vector<int>)': main.cpp:69:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(n_<a.size()+b.size())n_=n_*2; ~~^~~~~~~~~~~~~~~~~~ main.cpp:75:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(a.size()>i)a_.push_back({a[i],0}); ~~~~~~~~^~ main.cpp:79:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(b.size()>i)b_.push_back({b[i],0}); ~~~~~~~~^~ main.cpp: In function 'int main()': main.cpp:124:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("chimichangas.in","r",stdin); ^ main.cpp:125:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("chimichangas.out","w",stdout); ^ main.cpp:127:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i",&n,&k); ^ main.cpp:130:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%i",&cal[i]); ^ main.cpp:139:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%i",&q); ^ main.cpp:143:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%i",&w); ^