Compilare: user.cpp: In function ‘bool Ok(cell)’: user.cpp:20:24: warning: suggest parentheses around comparison in operand of ‘|’ [-Wparentheses] if(w.lin<1 || w.lin>n | w.col<1 || w.col>m || a[w.lin][w.col]) return false; ^ user.cpp: In function ‘int main()’: user.cpp:77:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("car.in","r",stdin); ^ user.cpp:78:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("car.out","w",stdout); ^ user.cpp:79:75: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d%d%d", &n,&m,&start.lin,&start.col,&stop.lin,&stop.col); ^ user.cpp:83:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i][j]); ^