c语言问题,关于printf语句的输出答:printf("a=%f\n", b);printf("b(%%f)=%f, b(%%lf)=%lf, b(%%5.4lf)=%5.4lf, b(%%e)=%e\n\n",b,b,b,b);printf("c=%f\n", c);printf("c(%%lf)=%lf, c(%%f)=%f, c(%%8.4lf)=%8.4lf\n\n",c,c,c);printf("d=%c\n", d);printf("d(%%c)=%c,...
找规律,1,4,10,20,35……求第n个数答:an=n(n+1)(n+2)/6要解答过程A1=1=C(3,3) A2=4=C(4,3) A3=10=C(5,3) A4=20=C(6,3) A5=35=C(7,3) A6=56=C(8,3) A7=84=C(9,3) A8=120=C(10,3) 所以规律是组合数C(n+2,3)=(n+2)(n+1)n/3! 即An=n(n+1)(n+2)/6。等差数列(英文:arithmetic ...