Compilare: main.cpp: In function 'int main()': main.cpp:57:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(v.size()<=k) ~~~~~~~~^~~ main.cpp:69:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=n&&ans.size()<k;++i) ~~~~~~~~~~^~ main.cpp:41:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("salvare.in","r",stdin); ^ main.cpp:42:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("salvare.out","w",stdout); ^ main.cpp:43:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&k); ^ main.cpp:47:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^