Compilare: user.cpp: In function ‘int main()’: user.cpp:85:15: warning: unused variable ‘j’ [-Wunused-variable] int n,m,i,j,l; ^ user.cpp:85:17: warning: unused variable ‘l’ [-Wunused-variable] int n,m,i,j,l; ^ user.cpp:83:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("teroristi.in","r",stdin); ^ user.cpp:84:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("teroristi.out","w",stdout); ^ user.cpp:88:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d\n",&n,&m); ^ user.cpp:89:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ user.cpp:100:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%c %c\n",&c1,&c2); ^ /tmp/ccc6vjCY.o: In function `main': user.cpp:(.text.startup+0x72): warning: the `gets' function is dangerous and should not be used.