Compilare: user.cpp: In function ‘int main()’: user.cpp:17:40: 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:18:42: 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:20:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:21:5: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (int i = 1; i <= n; scanf("%lld", &a[i]), i++); ^ user.cpp:22:5: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (int i = 1; i <= m; scanf("%lld", &b[i]), i++); ^