实验6-3 使用函数求特殊a串数列和 (20分)

http://pta.patest.cn/pta/test/13/exam/3/question/475

#include <stdio.h>

#include<math.h>

int fn( int a, int n );

int SumA( int a, int n );

int main()

{

    int a, n;

    scanf("%d %d", &a, &n);

    printf("fn(%d, %d) = %d\n", a, n, fn(a,n));

    printf("s = %d\n", SumA(a,n));

    return 0;

}

int fn( int a, int n )

{
int sum=0,i,b=1;
for(i=0;i<n;i++)
{
//b=b*10;
sum=sum+a*b;
b=b*10;
}
return sum;

}

int SumA( int a, int n )

{
int sum1=0,sum2,i;
for(i=1;i<n+1;i++)
{
sum2=fn(a,i);
sum1=sum1+sum2;

}
return  sum1;

}