我写的哈夫曼编码遇到权值相同的结点，其中会有一个随机的结点不输出他的编码（直接输出一个空行），这是为什么？要怎么解决呢？
代码：
#include<stdio.h>
#include<stdlib.h>
#define MAX 500

typedef struct List{
    char c;
int d;
char t[10];
}List;

List L[500];

typedef struct BTree{
    int data;
struct BTree* left;
struct BTree* right;
}BTree;

BTree* CreateBTree(int n) {
    int i, j;
    BTree **b, *q = NULL;
    b = (BTree**)malloc(n * sizeof(BTree));
    for (i = 0; i<n; i++) {//初始化b
        b[i] = (BTree*)malloc(sizeof(BTree));
        b[i]->data = L[i].d;
        b[i]->left = b[i]->right = NULL;
    }
    for (i = 1; i<n; i++) {//建立哈夫曼树
        int k1 = -1, k2 = 0;//k1表示最小权值结点下标，k2为次最小的下标
        for (j = 0; j<n; j++) {//k1初指向第一棵，k2指向第二棵
            if (b[j] != NULL&&k1 == -1) {
                k1 = j;
                continue;
            }
            if (b[j] != NULL) {
                k2 = j;
                break;
            }
        }
        for (j = k2; j<n; j++) {//从森林中求出最小权值树和次最小
            if (b[j] != NULL) {
                if (b[j]->data<b[k1]->data) {
                    k2 = k1;
                    k1 = j;
                }
                else if(b[j]->data<b[k2]->data)
                    k2 = j;
            }
        }
        q = (BTree*)malloc(sizeof(BTree));
        q->data = b[k1]->data + b[k2]->data;
        q->left = b[k1];
        q->right = b[k2];
        b[k1] = q;//将指向新树的指针赋给b指针数组中k1位置
        b[k2] = NULL;
    }
    free(b);//删除动态建立的数组b
    return q;
}

void HuffMan(BTree* FBT, int len, int n) {//len初始值为0
    static char a[10];//保存每个叶子的编码
    if (FBT != NULL) {
        if (FBT->left == NULL&&FBT->right == NULL) {
            int i;
            for (i = 0; i<n; i++)
                if (FBT->data == L[i].d)
                    break;
            for (int j = 0; j<len; j++)
                L[i].t[j] = a[j];
        }
        else {//向左右子树递归调用，并把编码保存到数组中
            a[len] = '0';
            HuffMan(FBT->left, len + 1, n);
            a[len] = '1';
            HuffMan(FBT->right, len + 1, n);
        }
    }
}

int main() {
    int n;
    BTree* Huf;
    printf("输入结点个数：\n");
    scanf("%d", &n);
    getchar();
    for (int i = 0; i<n; i++) {
        printf("");
        printf("输入结点以及其频率，中间以逗号隔开，例如：c，3\n");
        scanf("%c,%d", &L[i].c, &L[i].d);
        getchar();
    }
    Huf = CreateBTree(n);
    HuffMan(Huf, 0, n);
    for (int i = 0; i<n; i++)
    {
        printf("本行结果为频度：%d\n",L[i].d);
        printf("本行结果为字符：%c\n",L[i].c);
        printf("本行结果为编码：%s\n",L[i].t);
    }
    return 0;
}