It’s universally acknowledged that there’re innumerable trees in the campus of HUST.In HUST there is a famous road named YuYuan Rd linking the west campus with the east. Different types of trees are planted aside the road symmetrically. Each pair of trees on this road are given a value ai, specifying the type of trees in position i from west to east. One day, Coach Yin goes back to the dormitory from No.9 building at lunchtime. Unfortunately, he fails in finding the grandiose YunYuan Hotel. What he only remembers is the type of trees in the front of the hotel, which is an interval of the sequence described before. Moreover, he cannot classify types of tree correctly, and may identify several type of tree with other numbers. In specific, positions with different numbers are still different, while positions with same value remain consistent. Coach Yin loves the food in YunYuan Hotel. You should tell him how many places he should go to find out the hotel.
It’s universally acknowledged that there’re innumerable trees in the campus of HUST. In HUST there is a famous road named YuYuan Rd linking the west campus with the east. Different types of trees are planted aside the road symmetrically. Each pair of trees on this road are given a value ai, specifying the type of trees in position i from west to east. One day, Coach Yin goes back to the dormitory from No.9 building at lunchtime. Unfortunately, he fails in finding the grandiose YunYuan Hotel. What he only remembers is the type of trees in the front of the hotel, which is an interval of the sequence described before. Moreover, he cannot classify types of tree correctly, and may identify several type of tree with other numbers. In specific, positions with different numbers are still different, while positions with same value remain consistent. Coach Yin loves the food in YunYuan Hotel. You should tell him how many places he should go to find out the hotel.
