题解 | #牛牛学数列4#
牛牛学数列4
https://www.nowcoder.com/practice/586b114f52034688879342ba45779081
#include <stdio.h>
int main() {
int n, i,j,sum1=0,sum2=0;
scanf("%d",&n);
for(j=1;j<=n;j++)
{
sum1+=j;
sum2+=sum1;
}
printf("%d",sum2);
return 0;
}