Some similarities between the rich ruler and Zacchaeus are:
1) Both men were seekers of Jesus (Lk. 18:18; Lk. 19:2-3).
2) Both men were rich (Lk. 18:23; Lk. 19:2).
3) Both men were willingly receptive of Jesus (Lk. 18:18; Lk. 19:6).
4) Both men were seeking eternal life (Lk. 18:18; Lk. 19:8-10).
Some differences between the rich young ruler and Zacchaeus are:
1) The rich young ruler was not willing to share his riches with others less fortunate (deny himself – Matt. 16:24), in order to have riches in heaven and follow Jesus (Lk. 18:22).
In contrast, Zacchaeus was willing to deny self and share his riches with those less fortunate and restore anything taken by false accusation (Lk. 19:8).
2) The rich young ruler was very sorrowful – but not to the point of sincerely repenting of his selfishness. His was a worldly sorrow (Lk. 18:23; cf. 2 Cor. 7:10).
In contrast, Zacchaeus was sorrowful to the point of sincerely repenting of anything amiss in his life – even to the point of restoring to individuals anything falsely taken. His was a godly sorrow (Lk. 19:8-9; cf. 2 Cor. 7:9-10).