LeetCode | Climbing Stairs

题目

You are climbing a stair case. It takes n steps to reach to the top.

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

动态规划，斐波那契额数列

代码

public class ClimbingStairs {
	public int climbStairs(int n) {
		if (n <= 2) {
			return n;
		}
		int[] dp = new int[n];
		// init
		dp[0] = 1;
		dp[1] = 2;
		// dp
		for (int i = 2; i < n; ++i) {
			dp[i] = dp[i - 1] + dp[i - 2];
		}
		return dp[n - 1];
	}
}