Compilare: user.cpp: In function ‘int main()’: user.cpp:118:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < all_coords.size(); ++i) ^ user.cpp:102:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("popcorn.in", "r", stdin); ^ user.cpp:103:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("popcorn.out", "w", stdout); ^ user.cpp:107:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:109:51: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x[i].A, &x[i].B, &x[i].C); ^ user.cpp:141:57: warning: ‘sol’ may be used uninitialized in this function [-Wmaybe-uninitialized] printf("%lld", (long long) (round(solve(sol, 2) + m * sol))); ^