2019.11.17 training summary

I have been reviewing recently , It is very important to feel the transformation of thinking in the process of doing questions . For example, many seemingly complex problems of line segment trees , As long as it is handled skillfully, it becomes much simpler , For example, marking the line segment tree indicates the current status , In the process of query, the complexity can be greatly reduced . And the intersection , Change a continuous point into a discrete point ( discretization ）, It is easy to find the intersection point by arranging the vertical coordinates in the lower order . We should pay more attention to these ingenious methods in the future , It is often used .