Compilare: user.cpp: In function ‘int main()’: user.cpp:44:14: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(f[sir[i]]==0) ^ user.cpp:45:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] {k2++; f[sir[i]]++;} ^ user.cpp:47:14: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(f[sir[i]]==1) ^ user.cpp:48:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] {k1++; k2--; f[sir[i]]++; } ^ user.cpp:37:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cod2.in","r",stdin); ^ user.cpp:38:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cod2.out","w",stdout); ^ user.cpp:39:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&k); ^ user.cpp:40:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(sir+1); ^ /tmp/ccVMwF82.o: In function `main': user.cpp:(.text.startup+0x6a): warning: the `gets' function is dangerous and should not be used.