(Easy) N-th Tribonacci Number LeetCode

class Solution {
    public int tribonacci(int n) {
        
        if(n ==0){
            return 0;
            
        }
        
        if (n ==1){
            return 1;
        }
        
        if(n ==2){
            return 1;
        }
        
        int [] dp = new int[n+1];
        
        dp[0] =0;
        dp[1] =1;
        dp[2] =1;
        
        for(int i =3; i<=n;i++){
            dp[i]= dp[i-3]+dp[i-2]+dp[i-1];
        }
        
        return dp[n];
        
    }
}