Compilare: user.cpp: In function ‘int main(int, char**)’: user.cpp:47:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("culori3.in", "r", stdin); ^ user.cpp:48:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("culori3.out", "w", stdout); ^ user.cpp:50:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp: In function ‘int f(int, int)’: user.cpp:25:20: warning: ‘ans’ may be used uninitialized in this function [-Wmaybe-uninitialized] mem[p][c] = ans; ^