HackerRank Algorithms-Search-Flowers greedy

Q: K friends buy N more flowers. The boss is wonderful and doesn't want to buy too many flowers. If someone has already bought x flowers, the price of x + 1 is required to buy a flower. The price of each flower is given, and the minimum amount of money is required to buy the flower. Analysis: each small partner must first buy the original price when buying flowers, or else it will suffer. Therefore, the greedy strategy is to sort the prices first, so that each small partner can give a blood to the most expensive flowers, and each time they buy the most expensive flowers, this is the best. The complexity is O (n ). Code:

/** Author: Author z <iw.zen [at] gmail.com> * Blog: http://blog.csdn.net/hcbbt * File: Flowers. cpp * Lauguage: C/C ++ * Create Date: 2013-09-06 15:46:01 * Descripton: flowers */# include <cstdio> # include <algorithm> using namespace std; # define rep (I, n) for (int I = 0; I <(n); I ++) typedef long LL; typedef unsigned long ULL; const int MAXN = 110; int a [MAXN]; int n, k; LL sum = 0; bool cmp (int a, int B) {return a> B ;} int main () {scanf ("% d", & n, & k); rep (I, n) scanf ("% d ", & a [I]); sort (a, a + n, cmp); rep (I, n) sum + = a [I] * (I/k + 1 ); printf ("% lld \ n", sum); return 0 ;}