bzoj1724[Usaco2006 Nov]Fence Repair 切割木板

#include <iostream>
#include <cstring>
#include<cstdio>
#define fo(i,a,b) for(int i=a;i<=b;i++)
using namespace std;
int heap[100001],sz=0;
typedef long long ll;
int n;
inline void put(int y)
{
heap[++sz]=y;
int x=sz;
while (x>1&&heap[x>>1]>heap[x])
{
swap(heap[x],heap[x>>1]);
x>>=1;
}
}
inline int get()
{
int t=heap[1];
heap[1]=heap[sz--];
int x=1;
while (x<=(sz>>1))
{
int next=x<<1;
if (next<sz&&heap[next|1]<heap[next])next++;
if (heap[next]>=heap[x])return t;
swap(heap[next],heap[x]);
x=next;
}
return t;
}
int main()
{

scanf("%d",&n);
fo(i,1,n)
{
int x;
scanf("%d",&x);
put(x);
}
ll ans=0;
fo(i,1,n-1)
{
int x=get(),y=get();
put(x+y);
ans+=x+y;
}
printf("%lld\n",ans);
return 0;
}