Leetcode1984. Minimum difference in student scores

subject ：

To give you one Subscript from 0 Start Array of integers for nums , among nums[i] It means the first one i A student's grade . I'll give you another integer k .

Select any... From the array k A student's grade , Make this k Between scores The highest and Lowest score Of Difference value achieve To minimize the .

Return possible Minimum difference .

Investigation contents ： Sort + The sliding window

The main idea of the topic ： Take whatever in the array k It's worth , And then let this k The difference between the maximum value and the minimum value is the smallest .

Ideas ： Sort the array first , Think after sorting a[0] To a[k-1] this k It's worth , Suppose we put a[k-1] Replace with array subscript k-1 The number behind （ A number larger than him ）, Then the maximum value is determined by a[k-1] Become a larger number , And the minimum value does not change , Then the difference between the maximum value and the minimum value will become larger . So we use this method , from a[0]-a[0+k-1] To a[i]-a[ i+k-1=nums.size() ], Each calculation difference , Record the smallest one as ans.

The attached code ：

class Solution {
public:
    int minimumDifference(vector<int>& nums, int k) {
        int n=nums.size();
        sort(nums.begin(),nums.end());
        int ans=INT_MAX;
        for(int i=0;i+k-1<n;i++)
        {
            ans=min(ans,nums[i+k-1]-nums[i]);
        }
        return ans;
    }
};