Compilare: main.cpp: In function 'int main()': main.cpp:43:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("heavymetal.in", "r", stdin); ^ main.cpp:44:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("heavymetal.out", "w", stdout); ^ main.cpp:46:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%u", &n); ^ main.cpp:48:50: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%u %u", &v[i].start, &v[i].finish); ^