Bzoj 2257 [Jsoi2009] bottles and fuel

Title: http://www.lydsy.com/JudgeOnline/problem.php?id=2257

Test instructions: Given the capacity of N bottles, select the K to maximize the minimum volume that can be expressed between k bottles without a measure. k ≤ ≤ 1000 Capacity ≤9 。

Exercises
Consider two bottles (capacity isaAndb), the volume that can be represented by falling to each other is a value generated from two bottle capacityax+by, while(a,b)|ax+by, so the smallest volume is(a,b), extended to K bottles, the title is maximizedkThe maximum common factor of a bottle.
Consider each number decomposition factor to find the largest and at leastkThe second factor can be.
The time complexity of the map is not considered O(N max{V} ? ? ? ? ? ? ? √ ) 。

Code:

#include <map>#include <cstdio>#include <algorithm>using namespace STD; map<int, int>CntintN, K, x, I;intMain () {scanf("%d%d", &n, &k); while(n--) {scanf("%d", &x); for(i =1; I * i < x; ++i)if(x% i = =0) ++cnt[i], ++cnt[x/i];if(I * i = = x) ++cnt[i]; } map<int, int>:: Iterator it = Cnt.end (), JT = Cnt.begin (); for(--it,--JT; it! = JT;--it)if(It-second >= K) {printf("%d\n", it-first); Break; }return 0;}

Bzoj 2257 [Jsoi2009] bottles and fuel