text: Array to determine whether a state has been solved before
code: let v = new Array ( n ) ; for ( let i = 0 ; i < n ; i ++ ) { dp [ i ] = new Array ( n ) ; v [ i ] = new Array ( n ) ; for ( let j = 0 ; j < n ; j ++ ) { dp [ i ] [ j ] = 0 ; v [ i ] [ j ] = 0 ; } }