Compilare: user.cpp: In function ‘int main()’: user.cpp:111:10: warning: unused variable ‘a’ [-Wunused-variable] char a,flag; ^ user.cpp:115:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d " ,&t); ^ user.cpp:123:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d %d " ,&n,&m); ^