3.2

#include<stdio.h>
int main()
{
    int x=157,a,b,c,sum;
    a=x/100;
    b=(x-a*100)/10;
    c=x%10;
    sum=c*100+b*10+a*1;
    printf("a=%d,b=%d,c=%d,sum=%d\n",a,b,c,sum);
}