Description

Given the array nums, obtain a subsequence of the array whose sum of elements is strictly greater than the sum of the non included elements in such subsequence.

If there are multiple solutions, return the subsequence with minimum size and if there still exist multiple solutions, return the subsequence with the maximum total sum of all its elements. A subsequence of an array can be obtained by erasing some (possibly zero) elements from the array.

Note that the solution with the given constraints is guaranteed to be unique. Also return the answer sorted in non-increasing order.

Example 1:

Input: nums = [4,3,10,9,8]
Output: [10,9] 
Explanation: The subsequences [10,9] and [10,8] are minimal such that the sum of their elements is strictly greater than the sum of elements not included, however, the subsequence [10,9] has the maximum total sum of its elements.

Example 2:

Input: nums = [4,4,7,6,7]
Output: [7,7,6] 
Explanation: The subsequence [7,7] has the sum of its elements equal to 14 which is not strictly greater than the sum of elements not included (14 = 4 + 4 + 6). Therefore, the subsequence [7,6,7] is the minimal satisfying the conditions. Note the subsequence has to returned in non-decreasing order.

Example 3:

Input: nums = [6]
Output: [6]

Constraints:

  • 1 <= nums.length <= 500
  • 1 <= nums[i] <= 100

分析

题目的意思是：给定一个数字序列，找出一个子序列的和比剩下序列的和大的序列。找出符合条件的最小子序列。

  • 贪心法，对数组进行排序，从后往前找，先找大的数，用cur记录遍历的和，res记录遍历的值，当cur第一次大于数组的总和total的时候，说明找到了一个符合条件的res。

代码

class Solution {
public:
    int distributeCandies(vector<int>& candies) {
        unordered_set<int> s;
        int cnt=0;
        for(int candy:candies){
            s.insert(candy);
            cnt++;
        }
        return min((int)s.size(),cnt/2); 
    }
};

参考文献

​​【LeetCode】1403. 非递增顺序的最小子序列 Minimum Subsequence in Non-Increasing Order​​