Compilare: user.cpp: In function ‘int main()’: user.cpp:124:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<lit[i].size();j++){ ^ user.cpp:127:75: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(l<=SIGMA*SIGMA+1 &&(f[l][aux]==0 ||cnt[l]>=cart[l].size())){ ^ 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/ccFmYVk5.o: In function `main': user.cpp:(.text.startup+0x76): warning: the `gets' function is dangerous and should not be used.