Compilare: user.cpp: In function ‘int main()’: user.cpp:21:19: warning: unused variable ‘res’ [-Wunused-variable] long long res = 0; ^ user.cpp:11:14: warning: variable ‘fo’ set but not used [-Wunused-but-set-variable] FILE*fi,*fo; ^ user.cpp:15:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d", &n, &s); ^ user.cpp:17:54: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i = 0; i < n; i++) fscanf(fi,"%d", &v[i]); ^ user.cpp:18:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d", &m); ^ user.cpp:22:44: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d", &l, &r), l--, r--; ^