Compilare: user.cpp: In function ‘int main()’: user.cpp:15:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("suma.in", "r", stdin); ^ user.cpp:16:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("suma.out", "w", stdout); ^ user.cpp:18:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &N, &MOD); ^ user.cpp: In function ‘int sumPatImp(int)’: user.cpp:11:12: warning: ‘ANS’ may be used uninitialized in this function [-Wmaybe-uninitialized] return ANS; ^ user.cpp: In function ‘int main()’: user.cpp:27:20: warning: ‘ANS’ may be used uninitialized in this function [-Wmaybe-uninitialized] ANS =(ANS + (2 * sumPatImp (N - 1))) % MOD; ^