1137. N-th Tribonacci Number

The Tribonacci sequence Tn is defined as follows: 

T0 = 0, T1 = 1, T2 = 1, and Tn+3 = Tn + Tn+1 + Tn+2 for n >= 0.

GivenĀ n, return the value of Tn.

Example 1:


Input: n = 4
Output: 4
Explanation:
T_3 = 0 + 1 + 1 = 2
T_4 = 1 + 1 + 2 = 4

Example 2:


Input: n = 25
Output: 1389537
class Solution {
    public int tribonacci(int n) {
        if (n <= 1) {
            return n;
        }
        if (n ==2){
            return 1;
        }
        int cache[] = new int [n+1];
        cache[1] = 1;
        cache[2] = 1;
        for(int i=3;i<=n;i++) {
            cache[i] = cache[i-1] + cache[i-2] + cache[i-3];
        }
        return cache[n];
    }
}

https://leetcode.com/problems/n-th-tribonacci-number/description/?envType=study-plan-v2&id=dynamic-programming

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