Compilare: user.cpp: In function ‘int main()’: user.cpp:47:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxsubsum.in", "r", stdin); ^ user.cpp:48:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxsubsum.out", "w", stdout); ^ user.cpp:50:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld", &N, &M); ^ user.cpp:52:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &A[i]); ^ user.cpp:54:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld", &B[i]); ^ user.cpp: In function ‘std::vector<long long int> ssm(i64*, i64, i64&)’: user.cpp:41:3: warning: ‘r’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(i64 i = l; i <= r; ++ i) ^ user.cpp:15:7: warning: ‘l’ may be used uninitialized in this function [-Wmaybe-uninitialized] i64 l, r, st, dr; ^