Solution for c#: // the if !added at the end is in case the player is ranked in last position.

public static List climbingLeaderboard(List ranked, List player) { List playerRanks = new List(); int position = 0; int nextIndex = 0; int prev = -1;

    for(int i = player.Count-1; i >= 0; i--){
        bool added = false;
        for(int j = nextIndex; j < ranked.Count; j++){               
            if (player[i] >= ranked[j])
            {
                playerRanks.Add(position + 1);
                added = true;
                break;
            }
            nextIndex++;
            if(ranked[j] != prev){
                prev = ranked[j];
                position++;
            }               
        }
        if(!added){
           playerRanks.Add(position+1);
        }
    }

    playerRanks.Reverse();     
    return playerRanks;
}