Compilare: user.c: In function ‘main’: user.c:5:5: warning: format ‘%s’ expects argument of type ‘char *’, but argument 3 has type ‘char (*)[5000001]’ [-Wformat=] freopen("numar3.in","r",stdin),freopen("numar3.out","w",stdout),scanf("%d\n%s\n",&n,&s),t=s[0]; ^ user.c:5:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("numar3.in","r",stdin),freopen("numar3.out","w",stdout),scanf("%d\n%s\n",&n,&s),t=s[0]; ^ user.c:5:43: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("numar3.in","r",stdin),freopen("numar3.out","w",stdout),scanf("%d\n%s\n",&n,&s),t=s[0]; ^ user.c:5:74: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] freopen("numar3.in","r",stdin),freopen("numar3.out","w",stdout),scanf("%d\n%s\n",&n,&s),t=s[0]; ^