「NOI2015」荷马史诗 （k叉huffman树/k叉合并果子）

是个多叉huffman树，思想类比合并果子。

具体见 CrazyDave 的博客

CODE

#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
struct node {
	LL w, h;
	node(){}
	node(LL w, LL h):w(w), h(h){}
	inline bool operator <(const node &o)const {
		return w == o.w ? h > o.h : w > o.w;
	}
};
priority_queue<node>q;
int n, k;
int main () {
	scanf("%d%d", &n, &k);
	LL x, ans = 0;
	for(int i = 1; i <= n; ++i) {
		scanf("%lld", &x);
		q.push(node(x, 1));
	}
	int cnt = ((k-1) - (n-1)%(k-1)) % (k-1);
	while(cnt--) q.push(node(0, 1));
	cnt = q.size();
	while(cnt > 1) {
		LL w = 0, h = 0;
		for(int i = 1; i <= k; ++i)
			w += q.top().w, h = max(h, q.top().h), q.pop();
		ans += w;
		q.push(node(w, h+1));
		cnt -= k-1;
	}
	printf("%lld\n%lld\n", ans, q.top().h-1);
}