1.3 入门训练 序列求和
#include<stdio.h>//VC++6.0中不支持longlong
int main()
{
long long n,sum;
scanf("%lld",&n);
sum=(n+1)*n/2;
printf("%lld\n",sum);
return 0;
}
1.3 入门训练 序列求和
#include<stdio.h>//VC++6.0中不支持longlong
int main()
{
long long n,sum;
scanf("%lld",&n);
sum=(n+1)*n/2;
printf("%lld\n",sum);
return 0;
}