整型变量的定义与输出：整型变量a的值为-1，无符号整型变量b的值等于a，要求编程分别输出a和b的值。           求教

    int a = -1;
    unsigned int b = (unsigned int)a;
    printf("a=%d\nb=%u\n", a, b);

#include "stdio.h"
int main()
{
    int a=-1;
    unsigned short b;
    b=a;
    scanf("%u",b);
    printf("b=%u",b);
    return 0;
}

先按回车在输入a，在回车