数据结构之哈夫曼树

// stringtraining.cpp: 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 50;
struct hnode
{
    string code;
    int bit;
    int v;
    int left, right;
    int num;
    void init(int q)
    {
        v = q;
        left = -1;
        right = -1;
        bit = -1;
    }
    bool operator<(const hnode &oth)const
    {
        return v>oth.v;
    }
}huffman[maxn];
int tot = 0;
map<int, char>mp;
int n;
void getcode(int t, string s)
{
    string codet;
    codet += s;
    if (huffman[t].left == -1 && huffman[t].right == -1)
    {
        huffman[t].code += s;
        return;
    }
    if (huffman[t].left != -1)
    {
        string m1 = codet + "0";
        getcode(huffman[t].left, m1);
        huffman[t].code += s;
    }
    if (huffman[t].right != -1)
    {
        string m2 = codet + "1";
        getcode(huffman[t].right, m2);
        huffman[t].code += s;
    }
    return;
}
int main()
{
    scanf("%d", &n);
    priority_queue<hnode>pq;
    for (int i = 1; i <= n; i++)
    {
        char ch;
        int v;
        cin >> ch >> v;
        mp[i] = ch;
        huffman[i].init(v);
        huffman[i].num = i;
        pq.push(huffman[i]);

    }
    tot = n + 1;
    while (pq.size()>1)
    {
        hnode tmp1 = pq.top();
        pq.pop();
        huffman[tmp1.num].bit = 0;
        hnode tmp2 = pq.top();
        pq.pop();
        huffman[tmp2.num].bit = 1;
        int sum = tmp1.v + tmp2.v;
        hnode k;
        k.left = tmp1.num;
        k.right = tmp2.num;
        k.v = sum;
        k.bit = -1;
        k.num = tot++;
        huffman[tot-1] = k;
        pq.push(k);

    }
    hnode last = pq.top();
    pq.pop();
    string ss;
    ss.clear();
    getcode(last.num, ss);
    for (int i = 1; i <= n; i++)
    {
        cout << mp[i] << " " << huffman[i].code << endl;
    }
    return 0;
}