Stair-up problems

When someone goes up the stairs, one step can take 1, 2, or 3 steps. There are 10 steps in total. How many different steps are there from the ground to the top?

This question cannot be determined due to the poor arrangement and combination. I provide a method for your reference: You may wish to set up n-level steps, since only one or two or three steps can be taken at a time, assume that only the last step is required. There are three situations: one step is required and (n-1) is used) order, Walk Method and take n-1 order the same, there are f (n-1) Order walk; two only need to take two steps, the above analysis has F (n-2); three only need to take three steps, F (n-3); so take the N step f (n) = f (n-1) + f (n-2) + f (n-3) walking method; obviously, there is one way to take the level 1 step; there are two ways to take the level 2; there are four ways to take the level 3, as shown below: 1 1 1 1 2 1 3; so I listed the corresponding tables of the total number of steps and steps: 1 2 3 4 5 6 7 8 9 101 2 4 7 13 24 44 81 149 274 so there are 274 steps, isn't it incredible?