1673. GauB in Elementary School

单点时限: 2.0 sec

内存限制: 256 MB

Johann Carl Friedrich GauB (1777 – 1855) was one of the most important German mathematicians. For those of you who remember the Deutsche Mark, a picture of him was printed on the 10 – DM bill. In elementary school, his teacher J. G. Büttner tried to occupy the pupils by making them add up the integers from 1 to 100. The young GauB surprised everybody by producing the correct answers (5050) within seconds.

Can you write a computer program that can compute such sums really quickly?

Given two integers n and m, you should compute the sum of all the integers from n to m. In other words, you should compute


The first line contains the number of scenarios. Each scenario consists of a line containing the numbers n and m (-10^9 ≤ n ≤ m ≤ 10^9).


The output for every scenario begins with a line containing “Scenario #i:”, where i is the number of the scenario starting at 1. Then print the sum of all integers from n to m. Terminate the output for the scenario with a blank line.


1 100
-11 10
-89173 938749341
Scenario #1:
Scenario #2:
Scenario #3:

75 人解决,132 人已尝试。

95 份提交通过,共有 534 份提交。

4.8 EMB 奖励。

创建: 15 年,1 月前.

修改: 5 年,1 月前.

最后提交: 7 月,4 周前.

来源: TUD Programming Contest 2006, Darmstadt, Germany