Compilare: user.cpp: In function ‘void read()’: user.cpp:9:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biti3.in", "r", stdin); ^ user.cpp:10:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp: In function ‘void write()’: user.cpp:44:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biti3.out", "w", stdout); ^ user.cpp: In function ‘void solve()’: user.cpp:37:20: warning: ‘pos’ may be used uninitialized in this function [-Wmaybe-uninitialized] m -= s[pos - 1][a]; ^