Climbing Stairs

Problem

Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?

Example 1:

Input: n = 2
Output: 2
Explanation: There are two ways to climb to the top.
1. 1 step + 1 step
2. 2 steps

Example 2:

Input: n = 3
Output: 3
Explanation: There are three ways to climb to the top.
1. 1 step + 1 step + 1 step
2. 1 step + 2 steps
3. 2 steps + 1 step

Solution

This is a good example of fibonacci implementation.

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class Solution {
private int[] val = new int[46];
public int getValue(int n) {
if(n < 0) return 0;
if(val[n] == 0) {
val[n] = climbStairs(n);
}
return val[n];
}

public int climbStairs(int n) {
if(n <= 0) return 0;
if(n == 1) return 1;
if(n == 2) return 2;
return (getValue(n-1) + getValue(n-2));
}
}