从键盘上输入一个四位正数,按照千,百,十,个位输出各位数,并且求出各...答:include<stdio.h>void main(){ unsigned int a; printf("请输入一个四位正数:"); scanf("%d",&a);if (a>=1000&&a<=9999){printf("千位数为:%d\n百位数为:%d\n",a/1000,a%1000/100);printf("十位数为%d\n个位数为%d\n",a%100/10,a%10);printf("四位数的和为%d\...