Compilare: user.cpp: In function ‘int main()’: user.cpp:28:30: warning: format ‘%s’ expects argument of type ‘char*’, but argument 4 has type ‘char (*)[1020]’ [-Wformat=] scanf("%d%d\n%s",&n,&l,&s); ^ user.cpp:31:9: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] s[0]=NULL; ^ user.cpp:25:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("interzis.in","r",stdin); ^ user.cpp:26:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("interzis.out","w",stdout); ^ user.cpp:28:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n%s",&n,&l,&s); ^