I think I am picturing the situation in this task incorrectly. The validator claims I'm wrong, and the other 2 people asking questions in the help section have answers that are not only completely different than mine, but I also can't make sense of them based on how I am picturing this in my mind.
So there are 70 steps. We need to count the number of permutations of ways he can ascend the stairs. He can go either 1, 2, or 3 steps at a time. So for every group of 3 steps, his options are: [1 + 1 + 1], or [1 + 2] or [2 + 1] or [3] . So 4 possibilities. If we divide n by 3 (no fractional values), we end up with the total amount of groups of 3 that we have. So 4 possibilities multiplied by groups of 3, gives us the total amount of different ways of climbing the stairs, not counting a possible remainder of 1 or 2. Then we add a 1 or a 2 depending on the remainder: you can climb 1 step in only one way [1], and 2 steps in 2 ways [1+1] or [2].
Am I way off here?
package com.codegym.task.task39.task3904;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/*
Stairs
*/
public class Solution {
private static int n = 70;
public static void main(String[] args) {
System.out.println("The number of possible ascents for " + n + " steps is: " + numberOfPossibleAscents(n));
}
public static long numberOfPossibleAscents(int n) {
if (n == 0) {
return 1;
}
if (n < 0) {
return 0;
}
long threes = n / 3;
//System.out.println(threes);
long result = threes * 4;
long remainder = n - threes * 3;
if (remainder % 2 == 0) {
result +=2;
}
if (remainder % 3 != 0) {
result+=1;
}
return result;
// List<Integer> list = new ArrayList<>();
// list.add(1);
// if (n % 2 == 0) {
// list.add(2);
// }
// if (n % 3 == 0) {
// list.add(3);
// }
// return list.size();
}
}