Compilare: user.cpp: In function ‘int eval()’: user.cpp:80:4: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (_c1==c1) ^ user.cpp:76:4: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (_l1==l1) ^ user.cpp:86:29: warning: control reaches end of non-void function [-Wreturn-type] l1=_l1,l2=_l2,c1=_c1,c2=_c2;} ^ user.cpp: In function ‘int main()’: user.cpp:88:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zone.in","r",stdin); ^ user.cpp:89:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zone.out","w",stdout); ^ user.cpp:91:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&n); ^ user.cpp:93:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&v[i]); ^ user.cpp:96:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&m[i][j]); ^