Compilare: user.cpp: In function ‘int solve(const std::vector<interval>&)’: user.cpp:35:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < intervals.size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:64:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("carpetbomber.in", "r", stdin); ^ user.cpp:65:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("carpetbomber.out", "w", stdout); ^ user.cpp:67:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:69:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &t, &l, &r); ^