Compilare: main.cpp: In function 'void read()': main.cpp:28:10: warning: unused variable 'i' [-Wunused-variable] long i, x, y; ^ main.cpp:29:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld", &n, &m); ^ main.cpp:32:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld", &x, &y); ^ main.cpp: In function 'int main()': main.cpp:67:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.in", "r", stdin); ^ main.cpp:68:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.out", "w", stdout); ^