Compilare: main.cpp: In function 'int main()': main.cpp:23:13: warning: unused variable 'y' [-Wunused-variable] int n,k,i,x,y; ^ main.cpp:21:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("freakdebunic.in","r",stdin); ^ main.cpp:22:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("freakdebunic.out","w",stdout); ^ main.cpp:24:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&k); ^ main.cpp:26:37: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x),assert(x<=n),cnt[x]=1; ^