Interview question 17.14 Minimum number of K (almost double hundreds)

Interview questions 17.14. Minimum K Number

The question :

Design an algorithm , Find the smallest... In the array k Number . Return this in any order k It's all right .

Example ：

 Input ： arr = [1,3,5,7,2,4,6,8], k = 4
 Output ： [1,2,3,4]

Tips ：

• 0 <= len(arr) <= 100000
• 0 <= k <= min(100000, len(arr))

Their thinking

This problem only needs to be solved

1. Sort , Let the small one come first , The big one is behind
2. Only keep k number , Delete the rest

Code

class Solution {
    
public:
    vector<int> smallestK(vector<int>& arr, int k) {
    
        //1. Prioritize  
        sort(arr.begin(),arr.end());
        // Determine the subscript of the reserved number ( iterator )
        vector<int>::iterator it = arr.begin() + k;
        // Delete the extra number 
        arr.erase(it,arr.end());
        return arr;
    }
};