N-th Tribonacci Number

class Solution {
public:
    int tribonacci(int n) {
        if (n == 0) return 0;
        if (n < 3) return 1;
        int a = 0, b = 1, c = 1;
        for (int i = 3; i <= n; ++i) {
            int d = a + b + c;
            a = b; b = c; c = d;
        }
        return c;
    }
};

func tribonacci(n int) int {
    if n == 0 {
        return 0
    }
    if n < 3 {
        return 1
    }
    a, b, c := 0, 1, 1
    for i := 3; i <= n; i++ {
        d := a + b + c
        a, b, c = b, c, d
    }
    return c
}

class Solution:
    def tribonacci(self, n: int) -> int:
        if n == 0:
            return 0
        if n < 3:
            return 1
        a, b, c = 0, 1, 1
        for _ in range(3, n + 1):
            a, b, c = b, c, a + b + c
        return c

function tribonacci(n) {
    if (n === 0) return 0;
    if (n < 3) return 1;
    let a = 0, b = 1, c = 1;
    for (let i = 3; i <= n; i++) {
        const d = a + b + c;
        a = b; b = c; c = d;
    }
    return c;
}

class Solution {
    public int tribonacci(int n) {
        if (n == 0) return 0;
        if (n < 3) return 1;
        int a = 0, b = 1, c = 1;
        for (int i = 3; i <= n; i++) {
            int d = a + b + c;
            a = b; b = c; c = d;
        }
        return c;
    }
}

function tribonacci(n: number): number {
    if (n === 0) return 0;
    if (n < 3) return 1;
    let a = 0, b = 1, c = 1;
    for (let i = 3; i <= n; i++) {
        const d = a + b + c;
        a = b; b = c; c = d;
    }
    return c;
}