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2681. Put Marbles in Bags

HardOpen on LeetCodeProblem statement

Problem Statement

2681. Put Marbles in Bags

Hard


You have k bags. You are given a 0-indexed integer array weights where weights[i] is the weight of the ith marble. You are also given the integer k.

Divide the marbles into the k bags according to the following rules:

The score after distributing the marbles is the sum of the costs of all the k bags.

Return the difference between the maximum and minimum scores among marble distributions.

 

Example 1:

Input: weights = [1,3,5,1], k = 2
Output: 4
Explanation: 
The distribution [1],[3,5,1] results in the minimal score of (1+1) + (3+1) = 6. 
The distribution [1,3],[5,1], results in the maximal score of (1+3) + (5+1) = 10. 
Thus, we return their difference 10 - 6 = 4.

Example 2:

Input: weights = [1, 3], k = 2
Output: 0
Explanation: The only distribution possible is [1],[3]. 
Since both the maximal and minimal score are the same, we return 0.

 

Constraints:

C++

Source file
class Solution {
public:
    // placebo
    long long putMarbles(vector<int>& weights, int k) {
        int n = weights.size();
        if (k == 1 || n == k) return 0;
        vector<int> candidates;
        for (int i = 0; i < n-1; i++)
        {
            candidates.push_back(weights[i] + weights[i+1]);
        }
        sort(candidates.begin(), candidates.end());
        long long mins = 0, maxs = 0;
        for (int i = 0; i < k-1; i++)
        {
            mins += candidates[i];
            maxs += candidates[n-2-i];
        }
        return maxs - mins;
    }
};