class Solution {
    public int fib(int n) {
        if (n<=1) {
            return n;
        }
        
        int[] dp = new int[n+1];
        dp[0] = 0;
        dp[1] = 1;

        for (int i = 2; i <= n;i++) {
            dp[i] = dp[i-1] + dp[i-2];
        }

        return dp[n];
    }
}

class Solution {
    public int climbStairs(int n) {
        if (n<=1) {
            return n;
        }
        
        int[] dp = new int[n+1];

        dp[1] = 1;
        dp[2] = 2;

        for (int i = 3; i <= n;i++) {
            dp[i] = dp[i-1] + dp[i-2];
        }

        return dp[n];
    }
}

class Solution {
    public int minCostClimbingStairs(int[] cost) {
        int n = cost.length;
        int[] dp = new int[n+1];
        dp[0] = cost[0];
        dp[1] = cost[1];

        for (int i = 2; i < n; i++) {
            dp[i] = Math.min(dp[i-1],dp[i-2]) + cost[i];
        }

        return Math.min(dp[n-1],dp[n-2]);
    }
}