程序代码：

#include<stdio.h>
int main()
{
    unsigned width,precision;
    int number=256;
    double weight=242.5;
    
    printf("What field width？\n");
    scanf("%d",&width);
    printf("The number is:%*d:\n",width,number);
    printf("Niw enter a width and aprecision:\n");
    scanf("%d%d",&width,precision,weight);
    printf("Weight=%*.*f\n",width,precision,weight);/*这行*/
    return 0;
}