Until now, the most impressive error I have met occurred in the first year of university. In the first term, there was a course named C++. On that class, teacher required us to submit homework program on an acm’s website. On that website, the output of program must be exactly right in answer and format. Once, in a program submission, there always had a format error. However, I couldn’t find where the wrong is. The output was a sequence. It seems correct in answer, and the format. Under the effect of this error, I couldn’t accomplish the homework, which would lower my score.
I check the answer for three days without any result. Still, couldn’t find the problem. At last, I took a piece of paper and a pen. By simulating the computer, I reviewed all the processes from input to the output. Finally, I discover that there is an additional spacing at the end of the sequence. As a result of I start a new line after outputting the sequence, it wouldn’t show out. This was the error which had perplexed me for three days.
原文：http://www.cnblogs.com/jyc-blog/p/6476688.html