MaximumPointsYouCanObtainfromCards.java

class Solution {

    // TC : O(k)
    // SC : O(1)
    public int maxScore(int[] cardPoints, int k) {
        int sumOfKEls = 0;
        for(int i=0;i<k;i++){
            sumOfKEls = sumOfKEls + cardPoints[i];
        }
        int len = cardPoints.length;
        int maxSum = sumOfKEls;

        int i =0;
        while(i<k){
            sumOfKEls = sumOfKEls - cardPoints[k-i -1] + cardPoints[len-1-i];
            maxSum = Math.max(maxSum, sumOfKEls);
            i++;
        }

        return maxSum;
    }
}