Compilare: user.cpp: In function ‘int main()’: user.cpp:33:9: warning: unused variable ‘n’ [-Wunused-variable] int n,i,j,l,k,re=0,ma=0,x; ^ user.cpp:33:29: warning: unused variable ‘x’ [-Wunused-variable] int n,i,j,l,k,re=0,ma=0,x; ^ user.cpp:31:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("blis.in","r",stdin); ^ user.cpp:32:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("blis.out","w",stdout); ^ user.cpp:34:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&k); ^ user.cpp:36:15: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(si+1); ^ /tmp/ccBJ0A0s.o: In function `main': user.cpp:(.text.startup+0x74): warning: the `gets' function is dangerous and should not be used.