求Sn = a + aa + aaa + aaaa + aaaaa的前5项之和,其中a是一个数字,例如:2 + 22 + 222 + 2222 + 22222
#include<stdio.h> #pragma warning(disable:4996) int main() { int n; printf("Please input a number\n"); scanf("%d",&n); int i; int Sn = 0; int tmp = 0; for (i = 0; i < 5;i++) { tmp = tmp * 10 + n;//n,10n+n,10(10n+n)+n Sn += tmp;//n+(10n+n)+(10(10n+n)+n) } printf("Sn=%d\n",Sn); system("pause"); return 0; }