Compilare: user.cpp: In function ‘void f()’: user.cpp:26:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] {for(i=0;i<v[c[in]].size();i++) ^ user.cpp:15:16: warning: unused variable ‘j’ [-Wunused-variable] {int n,m,i,j,x,y,k,in,sf; ^ user.cpp:16:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:18:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {scanf("%d%d",&x,&y); ^ user.cpp: In function ‘int main()’: user.cpp:43:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] {freopen ("amici2.in","r",stdin); ^ user.cpp:44:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("amici2.out","w",stdout); ^ user.cpp:46:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^