Compilare: user.cpp: In function ‘int main()’: user.cpp:17:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(strlen(b+1)!=n) printf("NU\n"); ^ user.cpp:23:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] ap[a[i]]++; ^ user.cpp:32:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] ap[b[i]]++; ^ user.cpp:9:30: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("joben.in","r",stdin); ^ user.cpp:10:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("joben.out","w",stdout); ^ user.cpp:11:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&n1); ^ user.cpp:14:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(a+1); ^ user.cpp:15:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(b+1); ^ /tmp/ccNd2Xvn.o: In function `main': user.cpp:(.text.startup+0xb5): warning: the `gets' function is dangerous and should not be used.