Compilare: user.cpp: In function ‘int main()’: user.cpp:12:15: warning: unused variable ‘s’ [-Wunused-variable] int n, m, s = 0; ^ user.cpp:15:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &n, &m); ^ user.cpp:19:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &x, &y); ^