Compilare: user.cpp: In function ‘int main()’: user.cpp:19:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&n,&m); ^ user.cpp:20:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%c",&s[0]); ^ user.cpp:24:25: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s,2*m+1,f); ^