0323-2020-LEETCODE- interview 17.16- masseur problem - (DP)

Ideological renewal equation DP also thought of himself, but not a complete write.
Recurrence equation: dp [i] = Math.max ( dp [i - 1], dp [i - 2] + nums [i]);

Author: sweetiee
link: https: //leetcode-cn.com/problems/the-masseuse-lcci/solution/100-kong-jian-cong-onyou-hua-dao-o1bao-hui-by-swee/
two way , the second difficult to understand but more concise.

public int massage(int[] nums) {
        if (nums == null || nums.length ==0){
            return 0;
        }
        if (nums.length == 1){
            return nums[0];
        }
        int[] res = new int[nums.length];
        res[0] = nums[0];
        res[1] = Math.max(nums[0],nums[1]);
        for (int i = 2; i < nums.length; ++i) {
            res[i] = Math.max(res[i - 1],res[i - 2] + nums[i]);
        }
        return res[nums.length - 1];
    }

class Solution {
    public int massage(int[] nums) {
        int a = 0, b = 0;
        for (int i = 0; i < nums.length; i++) {
            int c = Math.max(b, a + nums[i]);
            a = b;
            b = c;
        }
        return b;
    }
}