text: Find the rightmost element which is smaller than the sum of two fixed elements The important thing to note here is , we use the previous value of k . If value of arr [ i ] + arr [ j - 1 ] was greater than arr [ k ] , then arr [ i ] + arr [ j ] must be greater than k , because the array is sorted .
code: while ( k < n && arr [ i ] + arr [ j ] > arr [ k ] ) ++ k ;