http://www.51nod.com/Challenge/Problem.html#problemId=1484

http://www.51nod.com/Challenge/Problem.html#problemId=1503

http://www.51nod.com/Challenge/Problem.html#problemId=1487

http://www.51nod.com/Challenge/Problem.html#problemId=1316

然后做完做下之前的线段树专题...