1423

class Solution {
public:
    int maxScore(vector<int>& cardPoints, int k) {
        int n=cardPoints.size(), minSum=INT_MAX;
        for(int i=1; i<n; i++)
            cardPoints[i] += cardPoints[i-1];

        if(n == k) return cardPoints[n-1];
        for(int i=n-k-1, j=-1; i<n; i++,j++){
            int diff = j>=0 ? cardPoints[i]-cardPoints[j] : cardPoints[i];
            minSum = min(minSum, diff);
        }
        return cardPoints[n-1]-((minSum==INT_MAX) ? 0 : minSum);
    }
};