变态跳台阶

https://www.nowcoder.com/practice/22243d016f6b47f2a6928b4313c85387

动态规划

public static int jumpFloor1(int target) {
    int[] dp = new int[target + 1];
    dp[0] = 1;
    dp[1] = 1;
    for (int i = 2; i <= target; i++) {
        dp[i] = 2 * dp[i - 1];
    }
    return dp[target];
}

递归

public static int jumpFloor2(int target) {
    if (target <= 1)
    return 1;
    return 2 * jumpFloor2(target - 1);
}