Huffman树 详见http://blog.youkuaiyun.com/shuangde800/article/details/7341289
然而我用小根堆过的
跟合并果子一样
#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<algorithm>
using namespace std;
long long i,j,k,m,n,a[20001],ans;
inline bool cmp(long long a,long long b){return a>b;}
inline long long readint()
{
char c=getchar();long long x=0;
while(c<'0'||c>'9')c=getchar();
while(c>='0'&&c<='9')x=x*10+c-'0',c=getchar();
return x;
}
int main()
{
n=readint();
for(i=1;i<=n;i++)a[i]=readint();
make_heap(a+1,a+n+1,cmp);
while(n>1)
{
pop_heap(a+1,a+n+1,cmp);
pop_heap(a+1,a+n,cmp);
a[n-1]+=a[n];
ans+=a[n-1];n--;
push_heap(a+1,a+n+1,cmp);
}
cout<<ans<<endl;
return 0;
}