Compilare: user.cpp: In function ‘int main()’: user.cpp:52:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] cat1[c][0]++; ^ user.cpp:53:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] A[c][cat1[c][0]]=i; ^ user.cpp:53:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] A[c][cat1[c][0]]=i; ^ user.cpp:58:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] ap[c]++; ^ user.cpp:59:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] aux=ap[c]; ^ user.cpp:60:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] x[i]=A[c][aux]; ^ user.cpp:44:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("swap.in","r",stdin); ^ user.cpp:45:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("swap.out","w",stdout); ^ user.cpp:46:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a+1); ^ user.cpp:47:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(b+1); ^ /tmp/ccFfVx7V.o: In function `main': user.cpp:(.text.startup+0x56): warning: the `gets' function is dangerous and should not be used.