poj2924---高斯求和

#include <stdio.h>
#include <stdlib.h>

int main()
{
int n,tim=0;
long long ans,a,b;
scanf("%d",&n);
while(n--)
{
scanf("%lld %lld",&a,&b);
ans = (a+b)*(b-a+1)/2;
printf("Scenario #%d:\n",++tim);
printf("%lld\n\n",ans);
}
}