huffman基础代码实现

#include <bits/stdc++.h>
using namespace std;
const int maxn=1e5+7;
const int INF=0x3f3f3f3f;
struct Huffman_Node{
   int ans;
   int father;
   int left;
   int right;
}H_Node[maxn];
int n;
void init()///初始化
{
   for (int i=0;i<(n+n-1);++i)
   {
     H_Node[i].father = -1;
     H_Node[i].left = -1;
     H_Node[i].right = -1;
   }
}
int H[maxn];
int main()
{
  scanf("%d",&n);
  init();
  memset(H,-1,sizeof(H));
  for(int i=0;i<n;++i)
  {
    scanf("%d",&H_Node[i].ans);
  }
  for (int j=1;j<n;++j)///n个叶子节点，最多合并n-1次
  {
    int m1 = INF;///最小的数
    int m2 = INF;///第二小的数
    int idx_1 = -1;
    int idx_2 = -1;
      for (int t=0;t<n+j-1;++t)
      {
        ///cout<<"fa"<<' '<<H_Node[t].father<<endl;
         if (H_Node[t].father==-1)
         {
            if (H_Node[t].ans < m1)
            {
               idx_2 = idx_1;
               idx_1 = t;
               m2 = m1;
               m1 = H_Node[t].ans;
            }
            else if (H_Node[t].ans < m2)
            {
               m2 = H_Node[t].ans;
               idx_2 = t;
            }
         }
      }
      /// cout<<idx_1<<' '<<idx_2<<endl;
      H_Node[n+j-1].ans = H_Node[idx_1].ans + H_Node[idx_2].ans;///合并概率
      ///cout<<H_Node[n+j-1].ans<<endl;
      H_Node[idx_2].father = n+j-1;
      H_Node[idx_1].father = n+j-1;
      H_Node[n+j-1].left = idx_1;
      H_Node[n+j-1].right = idx_2;
  }
  for (int i=0;i<n;++i)
  {
     int F=H_Node[i].father;
     ///cout<<F<<endl;
     int C=i;
     int cnt = n;
     while (F != -1)
     {
       if (H_Node[F].left==C)
       {
          H[--cnt]=0;
          ///cout<<0;
       }
       else
       {
          H[--cnt]=1;
          ///cout<<1;
       }
       C = F;
       F = H_Node[F].father;
     }
     for (int j=cnt;j<n;++j)
     {
       printf("%d",H[j]);
     }
     puts("");
  }
  return 0;
}