“任意输入一个三位数,输出这个三位数的百位、十位和个位,并且计算十位...答:printf("输入一个三位数:"); scanf("%d", &a); if (a > 999 || a < 100) printf("输入错误!"); else { b = a / 100; c = a / 10 % 10; d = a % 100 % 10; e = b + c + d; printf ("百位是%d,十位是%d,个位是%d,各个位数的和为%d", b, c, d, e); } return 0...