740. Delete and Earn

You are given an integer array nums. You want to maximize the number of points you get by performing the following operation any number of times:

• Pick any nums[i] and delete it to earn nums[i] points. Afterwards, you must delete every element equal to nums[i] - 1 and every element equal to nums[i] + 1.

Return the maximum number of points you can earn by applying the above operation some number of times.

Example 1:

Input: nums = [3,4,2]
Output: 6
Explanation: You can perform the following operations:
- Delete 4 to earn 4 points. Consequently, 3 is also deleted. nums = [2].
- Delete 2 to earn 2 points. nums = [].
You earn a total of 6 points.

Example 2:

Input: nums = [2,2,3,3,3,4]
Output: 9
Explanation: You can perform the following operations:
- Delete a 3 to earn 3 points. All 2's and 4's are also deleted. nums = [3,3].
- Delete a 3 again to earn 3 points. nums = [3].
- Delete a 3 once more to earn 3 points. nums = [].
You earn a total of 9 points.

Constraints:

• 1 <= nums.length <= 2 * 104
• 1 <= nums[i] <= 104

答案

这道题其实是打家劫舍的变种题，不过有一个值得注意的地方

func deleteAndEarn(nums []int) int {
   buckets := [10001]int{}

   for _, num := range nums {
      buckets[num] += num
   }

   fmt.Println(buckets)

   max := func(a, b int) int {
      if a > b {
         return a
      }
      return b
   }
   
   dp := [10001]int{}
   dp[1] = buckets[1]
   dp[2] = max(dp[1],buckets[2])

   

   for i := 3; i <= 10000; i++ {
      dp[i] = max(dp[i-1], dp[i-2]+buckets[i])
   }
   return dp[10000]

}