题解 | #最小的K个数#

解题思路：使用堆排序

class Solution {
public:
    void HeapAdjust(vector<int> &nums,int i,int heapsize) 
    {
        int left = 2*i+1;
        int right = 2*i+2;
        int smaller = i;
        if(left < heapsize && nums[smaller] >= nums[left])
            smaller = left;
        if(right < heapsize && nums[smaller] >= nums[right])
            smaller = right;
        if(smaller != i)
        {
            int temp = nums[smaller];
            nums[smaller] = nums[i];
            nums[i] = temp;
            HeapAdjust(nums, smaller, heapsize);
        }
    }  
    vector<int> GetLeastNumbers_Solution(vector<int> input, int k) {
        int n = input.size();
        for(int i = n/2;i>=0;--i)
            HeapAdjust(input, i, n);
        vector<int> res;
        for(int i = n-1;i>=n-k;--i)
        {
            res.push_back(input[0]);
            swap(input[0],input[i]);
            HeapAdjust(input, 0, i);
        }
        return res;
        
    }
};