Tribonacci.java

packagecom.thealgorithms.dynamicprogramming;

/**
 * The {@code Tribonacci} class provides a method to compute the n-th number in the Tribonacci sequence.
 * N-th Tribonacci Number - https://leetcode.com/problems/n-th-tribonacci-number/description/
 */
publicfinalclassTribonacci {
privateTribonacci() {
 }

/**
 * Computes the n-th Tribonacci number.
 *
 * @param n the index of the Tribonacci number to compute
 * @return the n-th Tribonacci number
 */
publicstaticintcompute(intn) {
if (n == 0) {
return0;
 }
if (n == 1 || n == 2) {
return1;
 }

intfirst = 0;
intsecond = 1;
intthird = 1;

for (inti = 3; i <= n; i++) {
intnext = first + second + third;
first = second;
second = third;
third = next;
 }

returnthird;
 }
}