exactnum [ i ] [ j ] [ k ] stores numbers of numbers having exact i 4 ' s , ▁ j ▁ 5' s and k 6 's
let exactnum = new Array ( N ) ; for ( let i = 0 ; i < N ; i ++ ) { exactsum [ i ] = new Array ( N ) ; exactnum [ i ] = new Array ( N ) ; for ( let j = 0 ; j < N ; j ++ ) { exactsum [ i ] [ j ] = new Array ( N ) ; exactnum [ i ] [ j ] = new Array ( N ) ; for ( let k = 0 ; k < N ; k ++ ) { exactsum [ i ] [ j ] [ k ] = 0 ; exactnum [ i ] [ j ] [ k ] = 0 ; } } }