Compilare: user.cpp: In function ‘void read()’: user.cpp:24:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("vecini2.in","r",stdin); ^ user.cpp:25:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&n); ^ user.cpp:26:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s\n%s\n",a,b); ^ user.cpp: In function ‘void write()’: user.cpp:92:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("vecini2.out","w",stdout); ^ user.cpp: In function ‘void solve()’: user.cpp:34:10: warning: ‘c’ may be used uninitialized in this function [-Wmaybe-uninitialized] char c; ^ user.cpp:52:16: warning: ‘p’ may be used uninitialized in this function [-Wmaybe-uninitialized] b1[p]=c; ^