本文实例讲述了基于C++实现的哈夫曼编码解码操作。分享给大家供大家参考，具体如下：
哈夫曼编码是一个通过哈夫曼树进行的一种编码，一般情况下，以字符：‘0'与‘1'表示。编码的实现过程很简单，只要实现哈夫曼树，通过遍历哈夫曼树，这里我们从每一个叶子结点开始向上遍历，如果该结点为父节点的左孩子，则在字符串后面追加“0”，如果为其右孩子，则在字符串后追加“1”。结束条件为没有父节点。然后将字符串倒过来存入结点中。
C++实现代码如下：
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#include<iostream>#include<string>using namespace std;struct Node{ double weight; string ch; string code; int lchild, rchild, parent;};void Select(Node huffTree[], int *a, int *b, int n)//找权值最小的两个a和b{ int i; double weight = 0; //找最小的数 for (i = 0; i <n; i++) { if (huffTree[i].parent != -1) //判断节点是否已经选过 continue; else { if (weight == 0) { weight = huffTree[i].weight; *a = i; } else { if (huffTree[i].weight < weight) { weight = huffTree[i].weight; *a = i; } } } } weight = 0; //找第二小的数 for (i = 0; i < n; i++) { if (huffTree[i].parent != -1 || (i == *a))//排除已选过的数 continue; else { if (weight == 0) { weight = huffTree[i].weight; *b = i; } else { if (huffTree[i].weight < weight) { weight = huffTree[i].weight; *b = i; } } } } int temp; if (huffTree[*a].lchild < huffTree[*b].lchild) //小的数放左边 { temp = *a; *a = *b; *b = temp; }}void Huff_Tree(Node huffTree[], int w[], string ch[], int n){ for (int i = 0; i < 2 * n - 1; i++) //初始过程 { huffTree[i].parent = -1; huffTree[i].lchild = -1; huffTree[i].rchild = -1; huffTree[i].code = ""; } for (int i = 0; i < n; i++) { huffTree[i].weight = w[i]; huffTree[i].ch = ch[i]; } for (int k = n; k < 2 * n - 1; k++) { int i1 = 0; int i2 = 0; Select(huffTree, &i1, &i2, k); //将i1，i2节点合成节点k huffTree[i1].parent = k; huffTree[i2].parent = k; huffTree[k].weight = huffTree[i1].weight + huffTree[i2].weight; huffTree[k].lchild = i1; huffTree[k].rchild = i2; }}void Huff_Code(Node huffTree[], int n){ int i, j, k; string s = ""; for (i = 0; i < n; i++) { s = ""; j = i; while (huffTree[j].parent != -1) //从叶子往上找到根节点 { k = huffTree[j].parent; if (j == huffTree[k].lchild) //如果是根的左孩子，则记为0 { s = s + "0"; } else { s = s + "1"; } j = huffTree[j].parent; } cout << "字符 " << huffTree[i].ch << " 的编码："; for (int l = s.size() - 1; l >= 0; l--) { cout << s[l]; huffTree[i].code += s[l]; //保存编码 } cout << endl; }}string Huff_Decode(Node huffTree[], int n,string s){ cout << "解码后为："; string temp = "",str="";//保存解码后的字符串 for (int i = 0; i < s.size(); i++) { temp = temp + s[i]; for (int j = 0; j < n; j++) { if (temp == huffTree[j].code) { str=str+ huffTree[j].ch; temp = ""; break; } else if (i == s.size()-1&&j==n-1&&temp!="")//全部遍历后没有 { str= "解码错误！"; } } } return str;}int main(){ //编码过程 const int n=5; Node huffTree[2 * n]; string str[] = { "A", "B", "C", "D", "E"}; int w[] = { 30, 30, 5, 20, 15 }; Huff_Tree(huffTree, w, str, n); Huff_Code(huffTree, n); //解码过程 string s; cout << "输入编码："; cin >> s; cout << Huff_Decode(huffTree, n, s)<< endl;; system("pause"); return 0;} |
运行结果如下：
希望本文所述对大家C++程序设计有所帮助。
原文链接：https://www.cnblogs.com/gyk666/p/6851821.html
