Following steps build L [ m + 1 ] [ n + 1 ] [ o + 1 ] in bottom up fashion . Note that L [ i ] [ j ] [ k ] contains length of LCS of X [ 0. . i - 1 ] and Y [ 0. . j - 1 ] and Z [ 0. . ... k - 1 ]
for ( int i = 0 ; i <= m ; i ++ ) { for ( int j = 0 ; j <= n ; j ++ ) { for ( int k = 0 ; k <= o ; k ++ ) { if ( i == 0 j == 0 k == 0 ) L [ i ] [ j ] [ k ] = 0 ; else if ( X [ i - 1 ] == Y [ j - 1 ] && X [ i - 1 ] == Z [ k - 1 ] ) L [ i ] [ j ] [ k ] = L [ i - 1 ] [ j - 1 ] [ k - 1 ] + 1 ; else L [ i ] [ j ] [ k ] = max ( max ( L [ i - 1 ] [ j ] [ k ] , L [ i ] [ j - 1 ] [ k ] ) , L [ i ] [ j ] [ k - 1 ] ) ; } } }