Assign Cookies

Sort both lists ascending. Let child point to the least greed factor not yet satisfied and cookie point to the smallest unused cookie. If the current cookie is smaller than greed[child], it cannot satisfy this child or any later child, so discard it by advancing cookie. Otherwise assign it, increment the count, and advance both pointers. The greedy choice is safe because giving a larger adequate cookie to the least demanding child can only reduce options for a more demanding one; the smallest adequate cookie leaves every larger cookie available. Test empty lists, more children than cookies, duplicate greed values, and cookies all too small or all large. Avoid pairing each child with the first arbitrary adequate cookie without sorting, which can waste a scarce size. Sorting dominates at O(g log g plus c log c) time, then the scan is O(g plus c); extra space is O(1) beyond sorting implementation details.