兄弟们！一个很简单的ｃ叠加问题～
题目是 1+（1+2）+（1+2+3）+........+(1+2+3+n)=?

我的程序如下　编译通过

但是结果却不对～兄弟们帮忙看看我错在那里了？


#include "stdio.h "
main()
{
int sum1,sum2,k1,k2,n;
sum1=0;
sum2=0;
printf ( "input number: \n ");
scanf ( "%d ",&n);
for (k1=1;k1 <=n;k1++)
{
for (k2=1;k2 <=k1;k2++)

sum2=sum2+k2;

sum1=sum1+sum2;
}
printf ( "%d ",sum1);
}

[解决办法]
int main()
{
int sum1,sum2,k1,k2,n;
sum1=0;
sum2=0;
printf ( "input number: \n ");
scanf ( "%d ",&n);
for (k1=1;k1 <=n;k1++)
{
sum2 = 0;//这里
for (k2=1;k2 <=k1;k2++)
sum2=sum2+k2;
sum1=sum1+sum2;
}
printf ( "%d ",sum1);
}