Compilare: user.cpp: In function ‘int main()’: user.cpp:68:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<vc[i].size();j++) ^ user.cpp:12:9: warning: unused variable ‘poz’ [-Wunused-variable] int x,y,poz,maxim=0; ^ user.cpp:12:13: warning: unused variable ‘maxim’ [-Wunused-variable] int x,y,poz,maxim=0; ^ user.cpp:9:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("johnie.in","r",stdin); ^ user.cpp:10:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("johnie.out","w",stdout); ^ user.cpp:11:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:15:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^