Me too!Have you solved this problem?

I have this WA too.
Firstly, I used binary search to find the last element, which didn't fall.

And my mistake was:
if (currentSum == k)
 return med;

the corrent ones:
if (currentSum == k)
 return med-1;

And for case, where we haven't found exactly k sum:

..
}//end of binary search

int answerIndex = l;
int sum = getSum(left, lastAdded Index);
if (sum <= k){
    answerIndex = l - 1;
}
return answerIndex;


But now I have TL11

5 1 4
1 2 3 4 5
5
ans: 8