Divide-and-conquer. One popular way to rank researchers is by their h-index. A researcher's h-index is the maximum integer k such that the researcher has at least k papers that have been cited at least k times each. Suppose a researcher X has written n papers and paper I has been cited ci times. Suppose you have these sorted in an array c with c1 >= c2 >= >= cn. Give a divide-and-conquer algorithm to nd researcher X's h-index. Your algorithm Must run in time (logn).