Mar 27 2009 16:04:45 GMT+0800

我们知道,一个分数分子一定时,分母值越小,其值越大.
2004/2005=1-1/2005
2005/2006=1-1/2006
2007/2008=1-1/2008
2007/2008-2005/2006=1-1/2008-(1-1/2006)=1/2006-1/2008>0
所以min(2005/2006,2007/2008)=2005/2006=1-1/2006
2005/2006-2004/2005=1-1/2006-(1-1/2005)=1/2005-1/2006>0
max[2004/2005,min(2005/2006,2007/2008)]=2005/2006