题解1013Sn求和

解题思路:循环嵌套

注意事项:

参考代码:

int main()

{

int n = 0;

int a = 2;

int i = 0;

int j = 0;

int mid = 0;

scanf("%d", &n);

int Sn = 0;

for (i = 0; i < n; i++)

{

mid = 0;

for (j = i; j >= 0; j--)

{

mid += a * (pow(10, j));

}

Sn = Sn + mid;

}

printf("%d",Sn);

return 0;

}