Compilare: main.cpp: In function 'int main()': main.cpp:28:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("xp.in", "r", stdin); ^ main.cpp:29:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("xp.out", "w", stdout); ^ main.cpp:33:44: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d%d", &n, &a1, &b1, &p, &q); ^