1137. 第 N 个泰波那契数.java

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