Compilare: user.cpp: In function ‘int main()’: user.cpp:30:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (bg<strlen(a)) ^ user.cpp:32:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while ((a[bg]<=a[bg+1])&&(bg<strlen(a))) bg++; ^ user.cpp:54:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=2; i<strlen(a); i++) ^ user.cpp:22:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("charlie.in","r",stdin); ^ user.cpp:23:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("charlie.out","w",stdout); ^ user.cpp:24:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld",&p); ^ user.cpp:25:14: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",a); ^