哈夫曼树_1172

题目描述：

哈夫曼树，第一行输入一个数n，表示叶结点的个数。需要用这些叶结点生成哈夫曼树，根据哈夫曼树的概念，这些结点有权值，即weight，题目需要输出所有结点的值与权值的乘积之和。

输入：

输入有多组数据。
每组第一行输入一个数n，接着输入n个叶节点（叶节点权值不超过100，2<=n<=1000）。

输出：

输出权值。

样例输入：

5  1 2 2 5 9

样例输出：

37

// Huffman2.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"#include <vector>#include <algorithm>#include <iostream>using namespace std;typedef struct tagHuffmanNode{int nWeight;//当前节点的权值int nParent;//父索引，便于从叶子到根得到Huffman编码int nLeft;//左右孩子int nRight;struct tagHuffmanNode() : nWeight(0), nParent(0), nLeft(0), nRight(0){}}HuffmanNode;void CalcFrequency(const char* str, int* pWeight){while(*str){pWeight[*str]++;str++;}}void CalcExistChar(int* pWeight, int N, vector<int>& pChar){int j = 0;for(int i = 0; i < N; i++){if(pWeight[i] != 0){pChar.push_back(i);if(j != i){pWeight[j] = pWeight[i];}j++;}}}void SelectNode(const HuffmanNode* pHuffmanTree, int n, int& s1, int &s2){s1 = -1;//无效值s2 = -1;int nMin1 = -1;//无效值int nMin2 = -1;for(int i = 0; i < n; i++){if((pHuffmanTree[i].nParent == 0) && (pHuffmanTree[i].nWeight > 0)){if((s1 < 0) || (nMin1 > pHuffmanTree[i].nWeight)){s2 = s1;nMin2 = nMin1;s1 = i;nMin1 = pHuffmanTree[s1].nWeight;}else if((s2 < 0) || (nMin2 > pHuffmanTree[i].nWeight)){s2 = i;nMin2 = pHuffmanTree[s2].nWeight;}}}}void HuffmanCoding(int *pWeight, int N, vector<vector<char> >& code) { if (N <= 0)return;int m = 2 * N - 1;//N个结点的Huffman树需要2N-1个结点HuffmanNode* pHuffmanTree = new HuffmanNode[m];int s1, s2;int i;//建立叶子结点for (i = 0; i < N; i++) pHuffmanTree[i].nWeight = pWeight[i];//每次选择权值最小的两个结点，建树for(i = N; i < m; i++){ SelectNode(pHuffmanTree, i, s1, s2);pHuffmanTree[s1].nParent = pHuffmanTree[s2].nParent = i;pHuffmanTree[i].nLeft = s1;pHuffmanTree[i].nRight = s2;pHuffmanTree[i].nWeight = pHuffmanTree[s1].nWeight + pHuffmanTree[s2].nWeight;}//根据建好的Huffman树从叶子到根计算每个叶结点的编码int node, nParent;for(i = 0; i < N; i++){vector<char>& cur = code[i];node = i;nParent = pHuffmanTree[node].nParent;while(nParent != 0){if(pHuffmanTree[nParent].nLeft == node)cur.push_back('0');elsecur.push_back('1');node = nParent;nParent = pHuffmanTree[node].nParent;}reverse(cur.begin(), cur.end());}}void PrintCode(char c, vector<char>& code){cout << (int)c << "   " << c << "：   ";for(vector<char>::iterator it = code.begin(); it != code.end(); it++){cout << *it;}cout << '\n';}void Print(vector<vector<char> >& code, vector<int>& pChar){int size = (int)code.size();for(int i = 0; i < size; i++){PrintCode(pChar[i], code[i]);}}int _tmain(int argc, _TCHAR* argv[]){const int N = 256;char str[] = "when I was young I'd listen to the radio\waiting for my favorite songs\when they played I'd sing along,\it make me smile.\those were such happy times and not so long ago\how I wondered where they'd gone.\but they're back again just like a long lost friend\all the songs I love so well.\every shalala every wo'wo\still shines.\every shing-a-ling-a-ling \that they're starting\to sing so fine";int pWeight[N] = {0};CalcFrequency(str, pWeight);pWeight['\t'] = 0;vector<int> pChar;CalcExistChar(pWeight, N, pChar);int N2 = (int)pChar.size();vector<vector<char> > code(N2);HuffmanCoding(pWeight, N2, code);Print(code, pChar);return 0;}

#include <iostream> #include <iomanip> #include <cmath> #include <string> #include <vector> #include <stack> #include <queue> #include <algorithm> #include <functional> using namespace std;   int main() {     int n, m;     while (cin >> n) {         priority_queue< int, vector<int>, greater<int> > Q;         for (int i = 0; i < n; ++i) {             cin >> m;             Q.push(m);         }           int sum = 0;         while (Q.size() > 1) {             int a = Q.top();             Q.pop();             int b = Q.top();             Q.pop();               sum += (a + b);             Q.push(a + b);         }           cout << sum << endl;     }      return 0; }