Given an array nums of integers, you can perform operations on the array.
In each operation, you pick any nums[i] and delete it to earn nums[i] points. After, you must delete every element equal to nums[i] - 1 or nums[i] + 1.
You start with 0 points. Return the maximum number of points you can earn by applying such operations.
Example 1:
Input: nums = [3, 4, 2]
Output: 6
Explanation:
Delete 4 to earn 4 points, consequently 3 is also deleted.
Then, delete 2 to earn 2 points. 6 total points are earned.
Example 2:
Input: nums = [2, 2, 3, 3, 3, 4]
Output: 9
Explanation:
Delete 3 to earn 3 points, deleting both 2's and the 4.
Then, delete 3 again to earn 3 points, and 3 again to earn 3 points.
9 total points are earned.
Note:
The length of nums is at most 20000.
Each element nums[i] is an integer in the range [1, 10000].
Solution:
class Solution {
public int deleteAndEarn(int[] nums) {
int[] buckets = new int[10001];
for (int val : nums) {
buckets[val] += val;
}
int[] dp = new int[10001];
dp[1] = buckets[1];
for (int i = 2; i <= 10000; i ++) {
dp[i] = Math.max(dp[i - 1], dp[i - 2] + buckets[i]);
}
return dp[10000];
}
}