3506: pSort
Description
One day n cells of some array decided to play the following game. Initially each cell contains a number which is equal to it's ordinal number (starting from 1). Also each cell determined it's favourite number. On it's move i-th cell can exchange it's value with the value of some other j-th cell, if |i-j|=di, where di is a favourite number of i-th cell. Cells make moves in any order, the number of moves is unlimited.
The favourite number of each cell will be given to you. You will also be given a permutation of numbers from 1 to n. You are to determine whether the game could move to this state.
The first line contains positive integer n (1≤n≤100) − the number of cells in the array. The second line contains n distinct integers from 1 to n − permutation. The last line contains n integers from 1 to n − favourite numbers of the cells.
If the given state is reachable in the described game, output YES, otherwise NO.
5
5 4 3 2 1
1 1 1 1 1
YES
7
4 3 5 1 2 7 6
4 6 6 1 6 6 1
NO
7
4 2 5 1 3 7 6
4 6 6 1 6 6 1
YES