Compilare: user.cpp: In function ‘int main()’: user.cpp:17:15: warning: unused variable ‘n’ [-Wunused-variable] int p,t,l,n,i,j,u,e,nr; ^ user.cpp:17:19: warning: unused variable ‘j’ [-Wunused-variable] int p,t,l,n,i,j,u,e,nr; ^ user.cpp:15:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cifra.in","r",stdin); ^ user.cpp:16:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cifra.out","w",stdout); ^ user.cpp:18:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&t); ^ user.cpp:30:18: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s+1); ^ /tmp/cc8ns11X.o: In function `main': user.cpp:(.text.startup+0x152): warning: the `gets' function is dangerous and should not be used.