UESTC Battery Charging (1647 )

import java.util.Scanner;

public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
long s,t,cnt,sum,i,cas = 0,n;
n = in.nextLong();
while (cas ++ < n) {
s = in.nextLong();
t = in.nextLong();
cnt = 0;
for(i = s;i <= t;i += (2*(i-1)+3))
{
if(i + (2*(i-1)+2) <= t)
cnt += i;
else
{
cnt += (((t-i-1)%2 == 1)?((t-i-1)/2 +1):((t-i-1)/2));
}
}
System.out.println("Case #"+cas+": "+cnt);
}
}
}