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1962. Remove Stones to Minimize the Total

MediumOpen on LeetCodeProblem statement

Problem Statement

1962. Remove Stones to Minimize the Total

Medium


You are given a 0-indexed integer array piles, where piles[i] represents the number of stones in the ith pile, and an integer k. You should apply the following operation exactly k times:

Notice that you can apply the operation on the same pile more than once.

Return the minimum possible total number of stones remaining after applying the k operations.

floor(x) is the greatest integer that is smaller than or equal to x (i.e., rounds x down).

 

Example 1:

Input: piles = [5,4,9], k = 2
Output: 12
Explanation: Steps of a possible scenario are:
- Apply the operation on pile 2. The resulting piles are [5,4,5].
- Apply the operation on pile 0. The resulting piles are [3,4,5].
The total number of stones in [3,4,5] is 12.

Example 2:

Input: piles = [4,3,6,7], k = 3
Output: 12
Explanation: Steps of a possible scenario are:
- Apply the operation on pile 2. The resulting piles are [4,3,3,7].
- Apply the operation on pile 3. The resulting piles are [4,3,3,4].
- Apply the operation on pile 0. The resulting piles are [2,3,3,4].
The total number of stones in [2,3,3,4] is 12.

 

Constraints:

C++

Source file
class Solution {
public:
    int minStoneSum(vector<int>& piles, int k) {
        priority_queue<int> pq;
        int res = 0;
        for(int i=0; i<piles.size(); i++){
            res+=piles[i];
            pq.push(piles[i]);
        }
        while(k--){
            int p = pq.top();
            pq.pop();
            res -= floor(p/2);
            p -= floor(p/2);
            pq.push(p);
        }
        return res;
    }
};