题解 | #小乐乐求和#
小乐乐求和
http://www.nowcoder.com/practice/ce0b2eacd3d04647831358c2876e44ff
#include<stdio.h>
int main()
{
long long int i =0,sum=0;
scanf("%lld",&i);
while(i--)
{
sum+=i+1;
}
printf("%lld\n",sum);
return 0;
}