Compilare: user.cpp: In function ‘void getxy(int&, int&)’: user.cpp:13:25: warning: NULL used in arithmetic [-Wpointer-arith] for(i = 0; ln[i] != NULL; ++ i) ^ user.cpp:18:20: warning: NULL used in arithmetic [-Wpointer-arith] for(; ln[i] != NULL; ++ i) ^ user.cpp:11:13: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(ln); ^ user.cpp: In function ‘int main()’: user.cpp:68:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ograzi.in", "r", stdin); ^ user.cpp:69:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ograzi.out", "w", stdout); ^ user.cpp:72:54: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d\n", &nOgr, &nOi, &height, &width); ^ /tmp/ccsZEjpn.o: In function `getxy(int&, int&)': user.cpp:(.text+0x61): warning: the `gets' function is dangerous and should not be used.