哈夫曼树的select函数和哈夫曼树的创建

[qq_33428266]

#include <iostream>
#include<stdio.h>
#include<string.h>
typedef char **HuffmanCode;
typedef struct
{
    int weight;
    int parent;
    int lchild;
    int rchild;
}HTNode,*HuffmanTree;
void select(HuffmanTree &HT,int m,int &S1,int &S2)
{
    int j;
    S1=0;
    S2=0;
    for(j=1;j<=m;j++)
    {
        while(HT[j].parent==0)
        {
            if(HT[j].weight<HT[S1].weight)
                S1=j;
        }
    }
    for(j=1;j<=m;j++)
    {
        while(HT[j].parent==0&&j!=S1)
        {
            if(HT[j].weight<HT[S2].weight)
                S2=j;
        }
    }

}
void CreateHuffmanTree(HuffmanTree &HT,int n,int &S1,int &S2)
{
    int m;
    int i;
    if(n<=1)
    {printf("叶子结点不足2个\n");
    return;}
    m=2*n-1;
    HT=new HTNode[m+1];
    for(i=1;i<m;i++)
    {
        HT[i].parent=0;
        HT[i].lchild=0;
        HT[i].rchild=0;
    }
    for(i=1;i<=n;i++)
    {
        printf("请输入第%d个叶子结点的权值(频率*100)\n",i);
        scanf("%d",&HT[i].weight);
    }
    /*初始化结束*/
    for(i=n+1;i<=m;i++)
    {
        select(HT,i-1,S1,S2);
        HT[S1].parent=i;
        HT[S2].parent=i;
        HT[i].lchild=S1;
        HT[i].rchild=S2;
        HT[i].weight=HT[S1].weight+HT[S2].weight;
    }
    printf("哈夫曼树创建完成\n");

}
void CreateHuffmanCode(HuffmanTree HT,HuffmanCode &HC,int n)
{
    int i,c,f;
    int start;
    char cd[n];
    HC=new char*[n+1];
    cd[n-1]='\0';
    for(i=1;i<n;i++)
    {
        start=n-1;
        c=i;f=HT[i].parent;
        while(f!=0)
        {
            --start;
            if(HT[f].lchild==c)
                cd[start]='0';
            else
                cd[start]='1';
            c=f;f=HT[f].parent;
        }
        HC[i]=new char[n-start];
        strcpy(HC[i],&cd[start]);
    }
    delete cd;
}
int main()
{
    int S1,S2;
    int n;
    HuffmanTree HT;
    HuffmanCode HC;
    printf("请输入叶子结点个数\n");
    scanf("%d",&n);
    CreateHuffmanTree(HT,n,S1,S2);
    CreateHuffmanCode(HT,HC,n);

}

[qq_33428266]

55-65行的for循环出不来。。。。死里面了、、、

[小灸舞]

卡在select函数里的while(HT[j].parent==0)
即没有修改j也没有修改parent所以跳不出while

[休止符x]

确实卡在Select函数里了

[千面如是。]

那怎么修改呢？

[坐端端同学]

void Select(HuffmanTree HT, int rear, int &s1, int &s2) {
//从HT[k]中选择双亲为0且权值最小的两个结点，并且返回他们在HT中的序号s1,s2
//其中1<=k<=rear
//要在双亲为0的结点中寻找，所以需要两遍循环寻找初始的min1和min2,作为比较的开始
int min1;
for (int i = 1; i <= rear; i++) {
if (!HT[i].parent) {//HT[i].parent==0
min1 = i;
break;
}

}
int min2;
for (int i = 1; i <= rear; i++) {
if ((!HT[i].parent)&&(i!=min1)) {//min1不能等于min2
min2 = i;
break;
}
}
//寻找第一个最小值
for (int i = 1; i <= rear; i++) {
if (HT[i].weight < HT[min1].weight && !HT[i].parent && (min2 != i)) {
min1 = i;
}
}

//寻找第二个最小值
for (int i = 1; i <= rear; i++) {
if (HT[i].weight < HT[min2].weight && !HT[i].parent&&(min1!=i)) {
min2 = i;
}
}

//打印寻找的最小值
s1 = min1;
s2 = min2;
cout <<"min1="<< min1 <<" min2=" << min2 << endl;
}