Compilare: user.cpp: In function ‘int main()’: user.cpp:15:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(a,"%d %d",&n,&m); ^ user.cpp:21:17: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(a,"%c",v); ^ user.cpp:25:18: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized] *(v+it)=x; ^