Math, play Huarong Road with children and tell me what you found.

There is more than one plan to let Cao Cao escape from Huarong Road. I want to find the one with the least steps, because the least is the best.

2. Huarong Road Game

Huarong Road, an ancient game in China, is called "Three Superman in Intelligence Games" by foreign intelligence experts, Rubik's Cube and Independent Diamond Chess because of its changeable and inexhaustible characteristics. It is also synonymous with traditional educational toys in China, such as jigsaw puzzles and nine-ring puzzle, which is called "China's jigsaw puzzle". The game of Huarong Road is taken from the famous story of Three Kingdoms. Cao Cao was defeated by Liu Bei and Sun Quan's "bitter plan" and "burning camp" in the Chibi War and was forced to retreat to Huarong Road. He was ambushed by Zhuge Liang. In order to repay Cao Cao's kindness, Guan Yu forced him to yield, and finally helped Cao Cao escape from Huarong Road.

This game is based on "Cao Zang was defeated, and he faced Guan Gong. Just for the story of "I was so grateful that I put down the golden lock and the dragon", I helped Cao Cao move from the initial position to the bottom middle of the chessboard and escaped from the exit by moving all the pieces. Don't allow the pieces to cross, and try to move Cao Cao to the exit with the least number of steps. The biggest obstacle for Cao Cao to escape from Huarong Road was Guan Yu, who immediately went to Huarong Road, and one person kept it, and no one could. Guan Yu and Cao Cao are, of course, the key to solving this game. The four soldiers of Liu Bei are the most flexible and easy to deal with. How to play their role should be fully considered.

"Huarong Road" has a chessboard with twenty small squares on it, representing Huarong Road. There is an exit with two squares under the chessboard, which is for Cao Cao to escape. There are ten pieces of different sizes on the chessboard, representing Cao Cao, Zhang Fei, Zhao Yun, Ma Chao, Huang Zhong and Guan Yu respectively, with a total of four pieces. There are dozens of ways to deal with Huarong Road, such as "cross the knife at once", "close at hand", "going through five customs to kill six generals", "packing" and "Xiaoyan leaving the nest" and so on. There are only two small squares on the chessboard. The game is to move the chess pieces through these two spaces and move Cao Cao out of Huarong Road with the least number of steps. This toy has aroused the interest of many people, and everyone tries to reduce the number of moving steps.

After decades of efforts by Chinese and foreign scientists such as Jiang, Fujimura Saburo, Martin Gadana, the game solution has been reduced from 87 steps more than 60 years ago to 8 1 step.