Returns length of LCS for X [ 0. . m - 1 ] , Y [ 0. . n - 1 ] and Z [ 0. . o - 1 ]
function lcsOf3 ( X , Y , Z , m , n , o ) { let L = new Array ( m + 1 ) ; for ( let i = 0 ; i < m + 1 ; i ++ ) { L [ i ] = new Array ( n + 1 ) ; for ( let j = 0 ; j < n + 1 ; j ++ ) { L [ i ] [ j ] = new Array ( o + 1 ) ; for ( let k = 0 ; k < o + 1 ; k ++ ) { L [ i ] [ j ] [ k ] = 0 ; } } }