POJ 3253

Huffman树 详见http://blog.csdn.net/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;}